JP2024127759A - Flow cytometer, biological sample analysis system, and optical detection device - Google Patents

Abstract

To reduce the size of a biological sample analysis system such as a flow cytometer.SOLUTION: The present disclosure provides a flow cytometer having a light detection device that detects light generated by irradiating biological particles flowing through a flow path with light. The light detection device has a plurality of light detector arrays in which light detector elements are arranged in a line. The plurality of light detector arrays are arranged at predetermined intervals along a direction intersecting an array direction of each light detector array. The present disclosure also provides a biological sample analysis system having the light detection device. The present disclosure also provides the light detection device.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to a flow cytometer, a biological sample analysis system, and an optical detection device. More particularly, the present disclosure relates to a flow cytometer and a biological sample analysis system that perform analysis based on light generated by irradiating biological particles with light, and an optical detection device used in the flow cytometer or the biological sample analysis system.

For example, particle characteristics are measured by labeling a particle population, such as cells, microorganisms, and liposomes, with a fluorescent dye, irradiating each particle in the particle population with laser light, and measuring the intensity and/or pattern of fluorescence emitted from the excited fluorescent dye. An example of a particle analyzer that performs such measurements is a flow cytometer.

Biosample analyzers such as flow cytometers analyze multiple particles one by one by irradiating the particles flowing in a line through a flow channel with laser light (excitation light) of a specific wavelength and detecting the fluorescence and/or scattered light emitted from each particle. In addition, based on the analysis results, desired bioparticles may be separated. Devices with a separation function are sometimes called cell sorters.

Such a biological sample analyzer has a light detection device for the analysis. Several technologies related to the light detection device have been disclosed so far. For example, the following Patent Document 1 discloses a fluorescence signal acquisition device (claim 1) that includes a plurality of light sources that irradiate a measurement object containing a plurality of fluorophores with a plurality of excitation light beams modulated by a carrier having different frequencies, a plurality of fluorescence detection units that detect a plurality of fluorescence beams generated in response to the plurality of excitation light beams, a multi-bandpass optical filter that is located in front of the plurality of fluorescence detection units and branches the plurality of fluorescence beams into a plurality of optical paths and transmits fluorescence from a plurality of fluorophores with discontinuous wavelengths, and a synchronous detection unit that synchronously detects the detection signals detected by each of the fluorescence detection units and separates the fluorescence corresponding to the plurality of fluorophores. The fluorescence detection unit is a photomultiplier tube (claim 11).

JP 2015-145829 A

Bioanalysis systems such as flow cytometers detect weak fluorescence and scattered light generated by cells. To detect such weak light, a sensitive photodetector is used. As mentioned above, for example, a photomultiplier tube (also called a PMT) is used as the photodetector.

The biological sample analysis system, which performs light detection using such a light detection device, is often large in size. This is particularly problematic when the biological sample analysis system is configured to irradiate biological particles with light from multiple light irradiation spots. For example, in such a biological sample analysis device, multiple light detection units are provided to detect light from each of the multiple light irradiation spots, which results in an increase in the number of light detection devices and an increase and complication of the configuration of the optical system for guiding light to each light detection device, and also results in an increase in the size of the biological sample analysis system.

There is a demand for miniaturizing the biological sample analysis system. By miniaturizing the biological sample analysis system, it becomes easier for users to use and allows for a wider range of experimental environments to be utilized. Therefore, an object of the present disclosure is to miniaturize the biological sample analysis system.

The present disclosure relates to
The device has a light detection device that detects light generated by irradiating light onto biological particles flowing through the flow path,
The light detection device includes a plurality of light detector arrays each having a line of light detector elements;
The plurality of photodetector arrays are arranged at predetermined intervals along a direction intersecting the array direction of each of the photodetector arrays.
A flow cytometer is provided.
The plurality of photodetector arrays may be arranged to correspond to a flow direction of the flow channel.
Each of the plurality of photodetector arrays comprises:
a photodetector array having a row of photomultiplier tube elements; or
a photodetector array having a row of avalanche photodiode elements; or
The photodetector array may be an array of photomultiplier tube elements arranged in a row, or an array of avalanche photodiode elements arranged in a row.
Each of the plurality of photodetector arrays may be a photodetector array in which photomultiplier tube elements are arranged in a line.
The photomultiplier tube element may be a photomultiplier tube element equipped with a dynode having a semiconductor element or a photomultiplier tube element equipped with a multi-stage dynode.
The light detection device may be a multi-pixel photon counter.
The flow cytometer may include a light irradiating unit that irradiates light onto bioparticles flowing through the flow channel at a plurality of light irradiation positions along a flow direction of the flow channel.
The plurality of light irradiation positions may be irradiated with light having wavelengths different from one another.
The flow cytometer may be configured to detect light resulting from light irradiation at two or more of the plurality of light irradiation positions using a single light detection device.
Each of the multiple photodetector arrays may be configured to have an adjustable gain independent of the others.
The photodetector array may be configured so that each of the multiple photodetector units can have a gain adjusted independently of the others.
One or more of the photodetector arrays may be configured such that their positions in a cross-array direction can be altered independently of one another.
One or more of the plurality of photodetector arrays may be configured such that the position of each of the photodetector arrays in the array direction can be changed independently of each other.
The light detection device may further comprise a microlens array;
The microlens array may be arranged such that each lens constituting the microlens array is located above a respective photodetector element of the light detection device.
The flow cytometer may have a propagation optical path that propagates light generated by the light irradiation to the light detection device,
The optical propagation path may include one or more optical fibers.
The flow cytometer comprises:
a light irradiation unit that irradiates light onto the bioparticles flowing through the flow path at a plurality of light irradiation positions along the flow direction of the flow path; and
The optical fiber may further include a propagation optical path through which light generated by the light irradiation by the light irradiation unit is propagated to the light detection device,
the propagation path includes a plurality of optical fiber core paths;
The light incident ends of the plurality of optical fiber core optical paths may be arranged to correspond to intervals between the plurality of light irradiation positions.
The flow cytometer comprises:
a light irradiation unit that irradiates light onto the bioparticles flowing through the flow path at a plurality of light irradiation positions along the flow direction of the flow path; and
The optical fiber may further include a propagation optical path through which light generated by the light irradiation by the light irradiation unit is propagated to the light detection device,
the propagation path includes a plurality of optical fiber core paths;
The light output ends of the plurality of optical fiber core paths may be arranged to correspond to the intervals of the photodetector array.
The flow cytometer may further include a propagation optical path that propagates light generated by irradiating light onto biological particles flowing through the flow path to the light detection device,
The propagation light path may pass through a field stop.
At least one of the plurality of photodetector arrays may have 10 or more photodetector units.
The multiple photodetectors included in the photodetection device may be configured to detect light independently of one another in time.
The present disclosure also provides
The device has a light detection device that detects light generated by irradiating light onto biological particles flowing through the flow path,
The light detection device includes a plurality of light detector arrays each having a line of light detector elements;
The plurality of photodetector arrays are arranged at predetermined intervals along a direction intersecting the array direction of each of the photodetector arrays.
A biological sample analysis system is also provided.
The present disclosure also provides
a photodetector array having a plurality of photodetector elements arranged in a line;
The plurality of photodetector arrays are arranged at predetermined intervals along a direction intersecting an array direction of each of the photodetector arrays, and
Used to detect light generated by irradiating biological particles flowing through a flow channel.
A light detection device is also provided.
The light detection device may be used in combination with a light irradiation unit that irradiates the bioparticles with light at a plurality of light irradiation positions along the flow direction of the flow channel.
The light detection device may be used in combination with a spectroscopic optical system that separates a plurality of light beams generated by light irradiation at the plurality of light irradiation positions.
Two or more of the photodetector arrays of the plurality of photodetector arrays may include at least one photodetector element having the same detection wavelength range.

FIG. 1 is a diagram illustrating an example of the configuration of a flow cytometer. FIG. 1 illustrates an example of the configuration of a flow cytometer according to the present disclosure. FIG. 1 is a diagram illustrating an example of the configuration of a light detection device. FIG. 1 is a diagram illustrating an example of the configuration of a light detection device. FIG. 1 is a diagram illustrating an example of the configuration of a hybrid photodetector. 4 is a schematic diagram for explaining a position irradiated with light by a light irradiating unit. FIG. FIG. 11 is a schematic diagram for explaining a change in position of the photodetector array. FIG. 11 is a schematic diagram for explaining a change in position of the photodetector array. FIG. 11 is a schematic diagram for explaining a change in position of the photodetector array. FIG. 13 is a schematic diagram showing a modified example of the light detection device. FIG. 13 is a schematic diagram showing a modified example of the light detection device. FIG. 1 is a diagram showing an example of the arrangement of a microlens array. FIG. 1 illustrates an example of the configuration of a flow cytometer according to the present disclosure. FIG. 1 is a diagram showing a schematic configuration example of an optical fiber bundle. 1 is a schematic diagram of an optical path of light to a photodetector designed by a spectroscopic optical system. 3 is a schematic diagram showing an incident surface when light guided by a spectroscopic optical system is incident on a light detection device. FIG. FIG. 13 is a schematic diagram showing a modified example of the light detection device. FIG. 1 illustrates an example of the configuration of a flow cytometer according to the present disclosure. 1 is a diagram showing roughly the overall configuration of a biological sample analyzer. 1 is a schematic diagram of an example optical fiber bundle. 1 is a schematic diagram of an example optical fiber bundle. 1 is a schematic diagram of an example optical fiber. 1 is a schematic diagram of an example optical fiber. 1 is a schematic diagram of an example optical fiber. 1 is a schematic diagram of an example optical fiber. 1 is a schematic diagram of an example optical fiber. 1 is a schematic diagram of an example optical fiber.

Preferred embodiments for carrying out the present disclosure will be described below. Note that the embodiments described below are representative embodiments of the present disclosure, and the scope of the present disclosure is not limited to these embodiments. Note that the present disclosure will be described in the following order.
1. First embodiment (flow cytometer)
(1) Basic configuration example (2) Configuration example of photodetector (3) Relationship with the light irradiation unit (4) Modifications of photodetector (4-1) Change in position (4-2) Modifications of photodetector array (4-3) Microlens array (5) Use of optical fiber (6) Design of optical path by spectroscopic optical system (7) Other configuration examples (use of multiple photodetectors)
(8) An embodiment without an objective lens (9) Configuration example of a flow cytometer 2. Second embodiment (biological sample analysis system)
3. Third embodiment (photodetector)

1. First embodiment (flow cytometer)

(1) Basic configuration example

As mentioned above, there is a demand for miniaturization of biological sample analysis systems such as flow cytometers. One of the main components of a biological sample analysis system is a detection unit that includes a light detection device that detects light emitted from biological particles. The detection unit can be a factor that leads to an increase in the size of the biological sample analysis system. Therefore, it is desirable to reduce the space occupied by the detection unit.

Examples of light detection devices include image sensors such as CCD and CMOS. However, the readout method of these image sensors is a frame method, so each pixel cannot be made to detect light independently. In addition, these image sensors do not have the sensitivity suitable for detecting weak light such as fluorescence generated by biological particles.

Photodetectors having a higher sensitivity than image sensors include photomultiplier tubes and avalanche photodiodes. The present inventors have found that a specific photodetection device having such a photodetector is suitable for use in a biological sample analysis system such as a flow cytometer.
That is, the present disclosure provides a biological sample analysis system having a photodetection device that detects light generated by irradiating light on biological particles flowing through a flow path, the photodetection device having a plurality of photodetector arrays in which photodetector elements are arranged in a line, and the plurality of photodetector arrays are arranged at predetermined intervals along a direction intersecting the array direction of each photodetector array.

In one embodiment, the biological sample analysis system may be a flow cytometer. The light detection device is suitable for detecting weak light such as fluorescent light and/or scattered light generated by irradiating light on biological particles (e.g., cells or liposomes) flowing through a flow channel, and is particularly suitable for detecting the biological particles when the biological particles are irradiated with light at multiple positions.

Use of the light detection device contributes to miniaturization of the biological sample analysis system, and in particular to miniaturization of the detection unit.
The photodetector device can be configured so that the gain of each photodetector element or each photodetector array can be adjusted independently. The signal strength of a fluorescent signal or the like may vary greatly depending on the wavelength. In such a case, the light of each wavelength can be kept within the dynamic range by adjusting the gain as described above.
Furthermore, the multiple photodetector elements included in the photodetection device may be configured to detect light independently of one another in time, whereby each photodetector element can detect light independently of one another in real time.

The present disclosure is described in more detail below with reference to the drawings.

The detection unit used in a flow cytometer may be configured, for example, as shown in Figure 1 below. This figure is a schematic overview of the detection unit.

A flow cytometer 100 shown in the figure is configured to irradiate light onto a bioparticle P flowing through a flow path C provided in a flow cell 110. In the figure, the bioparticle P flows in the direction of the dashed arrow.
The light irradiation unit (not shown) of the flow cytometer is configured to irradiate light at a plurality of positions. In the figure, three light irradiation positions S1 to S3 are shown. That is, the light irradiation unit is configured to irradiate light (particularly laser light) to each of the three light irradiation positions, and has, for example, three laser light sources. The laser light sources emit light of different wavelengths.
When a bioparticle P flows through the flow path C, the bioparticle passes through these light irradiation positions. During the passage, the particle is irradiated with light at each light irradiation position, and light is generated from the particle by the irradiation. The generated light passes through the objective lens 120, passes through the flow path side light guiding optical system 130, and reaches the optical fiber bundle 140.
The objective lens 120 is configured so that three light irradiation positions S1 to S3 exist within its field of view V. The flow channel side light guiding optical system 130 is a light guiding optical system that causes the light emitted from the objective lens 120 to reach the optical fiber bundle, which is the propagation light path. These may be configured in a manner known in the art, and can be configured appropriately by a person skilled in the art.

The optical fiber bundle 140 may be a bundle having optical fiber cores in a number corresponding to the number of photodetectors 180 (180-1, 180-2, and 180-3) described later, or may be a bundle having optical fiber cores in a number equal to or greater than the number of photodetectors 180. The bundle may be, for example, a bundle of multiple optical fibers each having one core, a clad surrounding the core, and a coating layer surrounding the clad. In this case, the optical fiber bundle 140 may have optical fibers in the same number as the number of photodetectors or in a number greater than the number of photodetectors.
Alternatively, the bundle may be a bundle of multiple core-clad sets, each having a core and a cladding surrounding the core, covered with a single coating layer. In this case, the optical fiber bundle 140 may have the same number of core-clad sets as the number of photodetectors or a number greater than the number of photodetectors.
Alternatively, instead of an optical fiber bundle, an optical fiber having multiple cores in one cladding may be used, in which case the number of cores in the fiber may be the same as or greater than the number of photodetectors.
At the flow path end EI of the optical fiber bundle 140, the positions of the optical fiber cores are fixed. In the figure, the optical fiber bundle is configured so that three cores EC1, EC2, and EC3 are arranged at a predetermined interval. The intervals between these cores correspond to the intervals between the light irradiation positions S1 to S3, and may be, for example, the intervals between the light irradiation positions S1 to S3 multiplied by a predetermined factor. The light incident on the flow path end EI travels toward the light detection device end EO1 to EO3.

The optical fiber bundle 140 is separated midway and branches into three optical fibers. The number of branches into the optical fibers after branching corresponds to the number of photodetectors. The flow cytometer in the figure has three photodetectors, and the optical fiber bundle 140 branches into three optical fibers to correspond to these.

The light emitted from the branched optical fiber 140-1 passes through the detector side light guide optical system light 150-1 and reaches the spectroscopic optical system 160-1.

The detector-side light-guiding optical system 150-1 is shown as one lens in the figure for simplification, but it is clear that the configuration of the detector-side light-guiding optical system is not limited to this. The detector-side light-guiding optical system may be configured to cause the light emitted from the optical fiber 140-1 to enter a desired position of the spectroscopic optical element 160-1, and this configuration may be appropriately designed by a person skilled in the art. For example, the detector-side light-guiding optical system may include one or more lenses and/or one or more mirrors.
In this specification, the detector side light guiding optical systems 150-1, 150-2, and 150-3 may be collectively referred to as 150.

The spectroscopic optical system 160-1 is shown as a reflective diffraction grating in the figure, but it is clear that the configuration of the spectroscopic optical system is not limited to this. The spectroscopic optical system has optical characteristics that disperse light into wavelengths, that is, it is sufficient to be a spectroscope, and the configuration may be appropriately designed by a person skilled in the art. The spectroscopic optical system disperses light into wavelengths, thereby obtaining optical data for each wavelength. For example, the spectroscopic optical system is not limited to a reflective diffraction grating, and may be a transmissive diffraction grating or a prism. The prism may be one prism, or may be a combination of multiple prisms.
In this specification, the spectroscopic optical systems 160-1, 160-2, and 160-3 may be collectively referred to as 160.

The light separated into wavelengths by the spectroscopic optical system reaches the telecentric condensing lens 170-1. The telecentric condensing lens collimates the optical axis of the separated light and emits it toward the photodetector 180-1. The telecentric condensing lens is shown as one lens in the figure, but it is clear to those skilled in the art that the configuration of the telecentric condensing lens is not limited to this. The telecentric condensing lens only needs to be configured to collimate the separated light, and the configuration may be appropriately designed by those skilled in the art. For example, the telecentric condensing lens may be one lens, but may also be configured of multiple lenses.
In this specification, the telecentric focusing lenses 170-1, 170-2, and 170-3 may be collectively referred to as 170.

As shown in the figure, the photodetector device 180-1 has a configuration in which multiple photodetector elements 181 are arranged in a row. In the figure, five photodetector elements are arranged in a row, but it will be clear to those skilled in the art that the number of elements arranged in the row is not limited to five. Each photodetector element may be, for example, a PMT. The photodetector element is used as a fluorescence channel. Photons incident from the entrance window of each PMT are converted into photoelectrons on the photoelectric surface, and after being amplified, are output as an electrical signal. The output electrical signal is used as optical data for bioparticle analysis by an information processing unit described below.

As described above for the light from the optical fiber 140-1, the light emitted from the optical fiber 140-2 also passes through the detector side light guiding optical system 150-2, the diffraction grating 160-2, and the telecentric focusing lens 170-2 and is detected by the photodetector 180-2.
As described above for the light emitted from the optical fiber 140-1, the light emitted from the optical fiber 140-3 also passes through the detector side light guiding optical system 150-3, the diffraction grating 160-3, and the telecentric focusing lens 170-3 and is detected by the photodetector 180-3.

The three laser light sources of the light irradiation unit are assigned to each of the three light detection devices 180-1 to 180-3. The light detection device 180-1 detects light generated by light irradiation of a biological particle at a light irradiation position S1 by one laser light source. The light detection devices 180-2 and 180-3 each detect light generated by light irradiation of a biological particle at a light irradiation position S2 by another laser light source and light generated by light irradiation of a biological particle at a light irradiation position S3 by yet another laser light source. In this way, the laser light sources and the light detection devices have a one-to-one relationship.
In order to perform light detection by the light detection device in this one-to-one relationship, various optical elements are provided as shown in the figure. For example, in order to allow light to reach each of the light detection devices 180-1 to 180-3, a set of a detector-side light guiding optical system, a spectroscopic optical system, and a telecentric condenser lens is provided on the optical path between the optical fiber and the light detection device. That is, the number of sets of light guiding optical systems, diffraction gratings, and condenser lenses increases according to the number of light detection devices. Therefore, the size of the flow cytometer tends to increase.

The flow cytometer according to the present disclosure includes a specific photodetection device. The photodetection device has a plurality of photodetector arrays in which photodetector elements are arranged in a row, and the plurality of photodetector arrays are arranged at predetermined intervals along a direction intersecting the array direction of each photodetector array. This allows the configuration of the optical system mounted in the flow cytometer to be made compact, and in particular the number of optical components such as the light guiding optical system, the spectroscopic optical system, and the telecentric focusing lens can be reduced, which contributes to the miniaturization of the flow cytometer.

A schematic configuration example of a flow cytometer according to the present disclosure is shown in FIG. 2. The flow cytometer 200 shown in the figure is configured to irradiate light onto a bioparticle P flowing through a flow path provided in a flow cell 210. The flow cytometer has an objective lens 220 and a flow path side light guiding optical system 230. The objective lens 220 is configured so that three light irradiation positions S1 to S3 exist within the field of view V. The flow cell 210, the objective lens 220, and the flow path side light guiding optical system 230 may be configured in the same manner as the flow cell 110, the objective lens 120, and the flow path side light guiding optical system 130 described above in FIG. 1, and the description thereof also applies to the flow cytometer 200.

The light emitted from the flow channel side light guiding optical system 230 passes through the field stop 240, the detector side light guiding optical system 250, the spectroscopic optical system 260, and the telecentric focusing lens 270, and reaches the light detection device 280.

The field stop 240 may be configured to limit the observation area, and may be provided with field stops A1 to A3 corresponding to the light generated by the light irradiation at the light irradiation positions S1 to S3, respectively. This makes it possible to prevent the leakage of unnecessary stray light.

The light that has passed through the field stop 240 reaches the detector-side light-guiding optical system 250. The detector-side light-guiding optical system 250 is configured to guide the light to the spectroscopic optical system 260. The above description of the detector-side light-guiding optical system 150 applies to the optical components that configure the detector-side light-guiding optical system 250. The detector-side light-guiding optical system 250 may include, for example, one or more collimating lenses that collimate the light and/or one or more lenses that enlarge or reduce an image of the light. The configuration of the detector-side light-guiding optical system 250 may be designed as appropriate by a person skilled in the art.
As shown in the figure, all three lights generated by light irradiation at the three light irradiation positions pass through the same detector-side light guiding optical system 250. In this manner, the flow cytometer of the present disclosure may be configured such that one detector-side light guiding optical system is used as an optical path for multiple lights generated by light irradiation at multiple light irradiation positions.

The light leaving the detector side light guiding optical system 250 reaches the spectroscopic optical system 260. The spectroscopic optical system 260 disperses the light and causes it to reach the telecentric focusing lens 270. The light is dispersed into wavelengths by the spectroscopic optical system. The above description of the spectroscopic optical system 160 applies to the optical components that constitute the spectroscopic optical system. As described above for the spectroscopic optical system 160, the spectroscopic optical system may be, for example, a diffraction grating (transmissive diffraction grating or reflective diffraction grating) or a prism.
When a prism is used as the spectroscopic optical system, the material constituting the prism can be suitably selected from known materials that can be used for prisms, such as glass materials, but among these, it is preferable to use a material with high internal transmittance. By using a material with high internal transmittance, it is expected that the loss of the amount of light incident on the prism can be reduced and the light can be effectively guided to the photodetector. In particular, by using a material with high internal transmittance on the short wavelength side, the influence of light attenuation that differs for each wavelength can be reduced. Furthermore, the amount of light attenuation during spectroscopic analysis can be reduced by applying an AR coating (anti-reflection coating) to the surface of the prism.
Furthermore, by using a highly dispersive material as the material for forming the prism, the light incident on the prism can be suitably separated into individual wavelengths, thereby reducing the number of prisms used in the optical path.
When a prism is used as the spectroscopic optical system, a prism designed in any shape can be used by adjusting the apex angle etc. depending on the purpose of use.
As shown in the figure, the three lights generated by light irradiation at the three light irradiation positions all pass through the same spectroscopic optical system 260 and are dispersed by the spectroscopic optical system. In this manner, the flow cytometer of the present disclosure may be configured such that one spectroscopic optical system is used as the optical path for the multiple lights generated by light irradiation at the multiple light irradiation positions.

The light separated by the spectroscopic optical system 260 reaches the telecentric condenser lens 270. The telecentric condenser lens 270 collimates the separated light and causes it to reach the photodetector 280. The telecentric condenser lens may be configured as described above for the telecentric condenser lens 170.
As shown in the figure, the three light beams generated by the light irradiation at the three light irradiation positions all pass through the same telecentric condensing lens 270 after passing through the spectroscopic optical system 260, and the traveling direction of the dispersed light beams is made parallel by the telecentric condensing lens. The parallel light beams reach the photodetector. In this manner, the flow cytometer of the present disclosure may be configured such that one telecentric condensing lens is used as the optical path of the multiple light beams generated by the light irradiation at the multiple light irradiation positions.

The figure also shows the configuration of the photodetector elements when viewed from the light incident surface W of the photodetector device 280. As shown in the area indicated by the symbol W in the figure, the photodetector device 280 has three photodetector arrays 282-1 to 282-3 in which a plurality of photodetector elements 281 are arranged in a row.
In the figure, five photodetector elements are arranged in a row in each photodetector array, but it will be apparent to those skilled in the art that the number of elements arranged in the row is not limited to 5. The number of elements may be appropriately selected by those skilled in the art depending on, for example, the desired number of fluorescence channels.
In addition, in the figure, the light detection device 280 has three light detector arrays, but the number of light detector arrays in one light detection device is not limited to three. The number of light detector arrays may be changed depending on, for example, the number of light irradiation positions. For example, the light detection device may have the same number of light detector arrays as the number of light irradiation positions. In some embodiments, the light detection device may have a number of light detector arrays smaller or larger than the number of light irradiation positions.
The photodetector element is used as a fluorescence channel. Photons incident on the photodetector element are converted to photoelectrons at the photoelectric surface, and then amplified and output as an electrical signal. The output electrical signal is used as optical data by an information processing unit described later, for example, for bioparticle analysis.

The light detection device 280 shown in FIG. 2 has three light detector arrays 280-1 to 280-3, each of which has light detector elements arranged in a row. The light detector array 280-1 is assigned to detect light generated by light irradiation at the light irradiation position S1, the light detector array 280-2 is assigned to detect light generated by light irradiation at the light irradiation position S2, and the light detector array 280-3 is assigned to detect light generated by light irradiation at the light irradiation position S3. As shown in the figure, the light irradiation positions S1 to S3 are lined up along the flow direction, and the light detector arrays 280-1 to 280-3 are also lined up in the same order. That is, the light detector arrays 280-1 to 280-3 are also lined up to correspond to the flow direction of the bioparticles.
These three photodetector arrays can also be considered to be arranged at predetermined intervals along a direction intersecting (particularly, a direction perpendicular to) the array direction of each photodetector array.
Thus, the photodetector device according to the present disclosure has a plurality of photodetector arrays in which photodetector elements are arranged in a row, and the plurality of photodetector arrays are arranged at predetermined intervals along a direction intersecting the array direction of each photodetector array.

The photodetector and the photodetector element of the photodetector are described in more detail below with reference to Figures 3A and 3B. Figure 3A shows a schematic diagram of an example of the configuration of the light receiving surface side of the photodetector, with arrows to explain dimensions and dots to indicate positions. Figure 3B shows the photodetector housed in a housing.

3A has a plurality of detector arrays 282-1 to 282-3 in which photodetector units 281 are arranged in a row. Each detector array has 10 photodetector units in the figure, but the number of photodetector units in each detector array is not limited to 10. Also, in the figure, the photodetector device 280 has three detector arrays, but the number of detector arrays in the photodetector device is not limited to three. Specific examples of the number of photodetector units in each detector array and the number of detector arrays in the photodetector device will be described separately later.
3B, the light detection device 280 may be configured as a module housed in a housing 285 having a window through which the light detector array 282 is exposed. The module may be connected to, for example, an information processing unit via a cable 286.

The multiple detector arrays 282-1 to 282-3 are arranged in a line along a direction DB (also called the "cross direction DB") that intersects with the array direction DA of each photodetector array. The array direction DA and the cross direction DB are described below.

As shown in the figure, each of the multiple detector arrays 282-1 to 282-3 is arranged so that the rows of photodetector elements of these detector arrays are approximately parallel. In other words, the array direction DA may mean a direction that is approximately parallel to the rows of photodetector elements that make up the detector array.

In addition, in the figure, three detector arrays 282 are arranged along a cross direction DB. That is, the cross direction DB may mean a direction that is not parallel to the row of the photodetector elements. More specifically, the multiple detector arrays 282 may be arranged so that a line connecting the center position (e.g., C1) of one detector array and the center position (e.g., C2) of an array adjacent to the one detector array (arranged closest to the one detector array) intersects with the array direction DA.
In the figure, the detector arrays 282-1 and 282-2 are arranged so that a line connecting the center position C1 of the detector array 282-1 and the center position C2 of the detector array 282-2 is perpendicular to the array direction DA. Also, the detector arrays 282-2 and 282-3 are arranged so that a line connecting the center position C2 of the detector array 282-2 and the center position C3 of the detector array 282-3 is perpendicular to the array direction DA. In other words, the centers of the three detector arrays are arranged to form a straight line, and these three detector arrays are arranged so that the straight line is perpendicular to the array direction DA.
As described below, these detector arrays may be repositioned in the array direction, i.e., the line connecting these center positions does not necessarily have to be perpendicular to the array direction, and may intersect to form an angle of less than 90°, as long as this is acceptable for light detection.

One or more, two or more, or three or more of the photodetector elements constituting each of the photodetector arrays 282-1, 282-2, and 282-3 may be configured to detect light of the same wavelength, and in particular may be used as the same fluorescence channel. For example, one or more, two or more, or three or more of the photodetector elements constituting the photodetector array 283-1 may be configured to detect the same wavelength range as one or more, two or more, or three or more of the photodetector elements constituting the photodetector arrays 283-2 or 283-3. For example, there may be one or more, two or more, or three or more photodetector elements in each photodetector array that are used as the same fluorescence channel.
In this manner, one or more, two or more, or three or more of the photodetector elements constituting each of the multiple photodetector arrays included in the photodetection device used in the present disclosure may be configured to detect light in the same wavelength range, and may be used in particular as the same fluorescence channel. Furthermore, five or more, ten or more, or fifteen or more of the photodetector elements constituting each of the multiple photodetector arrays may be configured to detect light in the same wavelength range.
Also, not all photodetector arrays need have the same number of photodetector elements, for example each photodetector array may have different photodetector elements, for example at least one of the photodetector arrays may have 5 or more, 10 or more, or 15 or more photodetector elements.
For example, more than half, more than two-thirds, more than three-quarters, or more than four-fifths of the photodetector elements constituting each of the multiple photodetector arrays may be configured to detect light in the same wavelength range.
In some embodiments, all of the photodetector elements constituting each of the multiple photodetector arrays of the photodetection device may be configured to detect light in the same wavelength range, and in particular may be utilized as the same fluorescence channel.
It should be noted that among each photodetector array, there may be one or more photodetector elements that do not detect light in the same wavelength range.

The advantages of having a flow cytometer with a photodetector configured in this way, as well as examples of how to use the photodetector and the flow cytometer, are described below.

1, each of the multiple photodetection devices has a photodetector array (a plurality of photodetector units arranged in a row). In this case, in order to guide light to each photodetection device and disperse the light, it is necessary to provide a number of light guiding optical systems, dispersing optical systems, and telecentric condensing lenses corresponding to the number of photodetection devices.
On the other hand, the flow cytometer shown in Fig. 2 has a single light detection device equipped with multiple detector arrays. This allows the number of light guiding optics, spectroscopic optics, and telecentric condensing lenses to be reduced. This allows the flow cytometer to be made more compact, particularly the detection unit.

Furthermore, for example, each detector array can acquire the spectrum of light (e.g., fluorescence spectrum) generated from the bioparticle, and furthermore, the spectrum of light (e.g., fluorescence spectrum) generated by irradiating the bioparticle with light from each of multiple excitation light sources (particularly multiple excitation light sources having different wavelengths) can be acquired.

Furthermore, a plurality of detector arrays may be arranged along a direction intersecting (particularly perpendicular to) the array direction, thereby making it possible to obtain images of bioparticles moving at high speed.
For example, each of the multiple photodetector elements constituting one detector array can be configured to acquire the signal intensity of light (e.g., the signal intensity of light of the same wavelength or the same wavelength range, particularly the signal intensity distribution in the direction across the flow path) generated by irradiating a biological particle with light at one light irradiation position. Then, the signal intensity is acquired over a predetermined time period to acquire distribution state data of the signal intensity at each time. By arranging the distribution state data along the time axis, two-dimensional image data of the biological particle can be acquired. That is, the photodetector array is used to scan the flowing particles.
Since the light detection device has a plurality of light detector arrays, each detector array may be configured to acquire light generated by irradiating a bioparticle with light (excitation light) having different wavelengths at a plurality of light irradiation positions, thereby acquiring a plurality of image data based on the light generated by irradiation with light of each wavelength.
Thus, a flow cytometer (particularly a light detection device) according to the present disclosure may be configured to acquire images of the bioparticles.

The optical detection device may have multiple detector arrays, and some of these detector arrays may be used to obtain the spectrum of light (particularly fluorescence) generated by irradiating the bioparticles with light as described above, and the remaining detector arrays may be used to obtain image data of the bioparticles as described above. In this way, a flow cytometer according to the present disclosure may have the optical detection device, and may be configured to obtain both spectral data and image data as described above.

The optical detection device can also be used to obtain position information when the bioparticle passes through the light irradiation position. The position information can be obtained based on signals obtained from each detector array, for example, by arranging each detector array perpendicular to the flow direction. To obtain the position information, for example, light of the same wavelength can be irradiated onto each of the multiple light irradiation positions, and the spectrum of the light in the flow direction can be obtained.

(2) Example of optical detection device configuration

An example of the configuration of the light detection device will be described in more detail below.
As shown in Figure 3A, the light detection device according to the present disclosure includes a detector array in which light detector elements are arranged in a row. The light detector elements may also be called light detector units. In other words, units having a function as a light detector may be arranged in a row.
The number of photodetector elements in each detector array may be, for example, 5 or more, preferably 10 or more, and more preferably 15 or more, in order to detect light separated into desired wavelengths.
The number of photodetector elements in each detector array is, for example, 100 or less, preferably 70 or less, more preferably 50 or less, for example, from the viewpoint of ease of manufacturing the photodetection device. In some embodiments, the number may be, for example, 45 or less, 40 or less, or 35 or less. The number of photodetector elements may be, for example, 64, 48, 32, 16, or 8, and in particular 32 or 16. The number of photodetector units corresponds, for example, to the number of fluorescence channels of a flow cytometer. Depending on the number of channels, the number of photodetector elements in each detector array may be changed.
Also, each detector array may be used as an equivalent to a detector array with a smaller number of photodetector elements by summing and processing signals obtained from multiple consecutive photodetector elements. By summing and processing signals in this manner, the detector array can be treated as an equivalent to a detector array with a smaller number of photodetector elements. In other words, the detector array can be made to correspond to the number of fluorescence channels without changing the number of photodetector elements.

Each photodetector element may be a photomultiplier tube or an avalanche photodiode. That is, all of the photodetector elements that make up each detector array may be photomultiplier tubes or avalanche photodiodes. In some embodiments, each detector array may include photomultiplier tubes and avalanche photodiodes.

In a preferred embodiment, each photodetector element may be a photomultiplier tube. That is, each of the plurality of photodetector arrays may be a photodetector array having a row of photomultiplier tube elements.

The photomultiplier element (hereinafter also referred to as a "photomultiplier tube") may be provided with a dynode having a semiconductor element. An example of a photomultiplier tube provided with a dynode having a semiconductor element is an HPD (Hybrid Photo Detector). An example of the configuration of an HPD will be described with reference to FIG. 4. The HPD 300 shown in the figure has an entrance window 301 through which light generated from a bioparticle enters, a photocathode 302 that emits electrons (photoelectrons) in response to the arrival of the light, a focusing electrode portion 303 that accelerates the photoelectrons, and a semiconductor element (particularly an avalanche diode) 304 that multiplies the electrons in response to the entrance of the electrons and outputs an electrical signal. The semiconductor element 304 may be fixed on a substrate 305. Furthermore, the substrate 305 may be fixed on a base 306. The HPD 300 further includes a power supply unit 307, a wire 308 that connects the power supply unit 307 to the substrate 305, and a signal extraction unit 309 that extracts a signal from the semiconductor element 304.

Light L incident from the entrance window 301 reaches the photocathode 302. When the light reaches the photocathode 302, photoelectrons E are emitted from the photocathode. The photoelectrons proceed toward the avalanche diode 304 while being accelerated by the focusing electrode portion 303. The semiconductor element 304 is configured to function as a dynode (electron multiplier portion). The semiconductor element 304 generates electron-hole pairs according to the incident energy of the photoelectrons. When photoelectrons are incident on the photoelectron entrance surface of the semiconductor element, the photoelectrons are multiplied by the semiconductor element and an electrical signal is output.
A photomultiplier unit equipped with a dynode having the semiconductor element has excellent unit photoelectron resolution and is particularly suitable for detecting weak light (particularly fluorescent or scattered light) generated from biological particles.

The photomultiplier unit may include multiple stages of dynodes. For example, a metal channel type or microchannel plate type photomultiplier may be used as such a photomultiplier. Such a photomultiplier is particularly suitable for detecting weak light generated from biological particles. In addition, a circular cage type, box type, line focus type, box line type, circular line type, or Venetian blind type photomultiplier may be used as the photomultiplier unit.

In another preferred embodiment, each photodetector unit may be an avalanche photodiode. That is, the photodetector array may be composed of a plurality of photodetector arrays in which avalanche photodiodes are arranged in a line. An example of a photodetector device in this embodiment may include, but is not limited to, a multi-pixel photon counter (MPPC).

In yet another preferred embodiment, the plurality of photodetector arrays may be composed of both a photodetector array in which photomultiplier tube units are arranged in a row and a photodetector array in which avalanche photodiode units are arranged in a row.

For example, the MPPC outputs signals from multiple avalanche photodiodes as a summed signal. On the other hand, for an array of photomultiplier tube elements, a signal can be output from each photomultiplier tube element. Therefore, preferably, the array of multiple photodetectors may be an array of photomultiplier tube elements. Alternatively, each element of the array may be composed of an MPPC.

The photodetector arrays may be configured to have independent gain adjustments for each of the photodetector arrays, i.e., the photodetection device may be configured to have gain adjustments for each array, which is particularly easy to perform when the photodetector elements are photomultiplier tubes or avalanche photodiodes.
When multiple laser beams with different wavelengths are irradiated onto a bioparticle, the signal strength of the fluorescence generated by the irradiation of each laser beam is often different. When one laser beam corresponds to one array, the signal output can be adjusted according to the intensity of the laser beam (or the signal strength of the light generated by the irradiation of the laser beam) by adjusting the gain for each array, which contributes to the ease of analyzing the optical data.
That is, a flow cytometer according to the present disclosure may be configured to adjust the gain of each photodetector array. For example, the flow cytometer may be configured to adjust the gain of each photodetector array based on the intensity of each light (particularly laser light) emitted from the light irradiation unit or based on the signal intensity of light generated by the light irradiation. For example, an information processing unit described below may obtain data regarding the intensity of each light or the signal intensity of light generated by the light irradiation, and adjust the gain of each photodetector array based on the data.

The photodetector array may be configured so that each of the photodetector elements can be adjusted in gain independently of one another. That is, the photodetector device may be configured so that gain adjustment can be performed for each photodetector element. The gain adjustment is particularly easy to perform when the photodetector elements are photomultiplier tubes or avalanche photodiodes.
The signal strength of the detected light may differ depending on the position in the array direction of a single photodetector array, so more appropriate analysis results can be obtained by adjusting the gain for each photodetector element in the detector array.
That is, a flow cytometer according to the present disclosure may be configured to adjust the gain of each photodetector element in the detector array. For example, the flow cytometer may adjust the gain of each photodetector element in the detector array based on the signal strength of light detected by each photodetector element. For example, an information processing unit described below may obtain data regarding the signal strength of light detected by each photodetector element, and adjust the gain of each photodetector element based on the data.

2 and 3, the light detection device 280 has a plurality of detector arrays 282 in which the light detector units 281 are arranged in a row. The number of detector arrays that the light detection device 280 has is not limited to 3 or 10 in these figures. The number of detector arrays may be the same as the number of light irradiation positions, for example, or may be the same as the number of types of laser light sources that the light irradiation unit has.
The number of detector arrays included in the light detection device may be, for example, two or more, preferably three or more, and more preferably four or more.
The upper limit of the number of detector arrays in the light detection device may not be particularly limited, but may be, for example, 20 or less, particularly 15 or less, and more particularly 10 or less, 9 or less, or 8 or less.

The light detection device may have a housing or a window configured to pass light generated by irradiating a biological particle with light. The shape of the housing or the window may be rectangular or circular as shown in the figure. The size L1 of the housing or the window may be, for example, 100 mm or less, preferably 80 mm or less, and more preferably 60 mm or less. The lower limit of the size L1 is not particularly limited and may be changed appropriately depending on, for example, the size and number of the photodetector array, and may be, for example, 5 mm or more, 10 mm or more, 20 mm or more, or 30 mm or more.
The size L1 is the length of one side or the long side when the shape of the housing or the passage window is rectangular, and means the diameter of the circle when the shape of the housing or the passage window is circular. Note that a circle includes a perfect circle and an ellipse. When the circle is an ellipse, the size means the major axis of the ellipse.

The multiple photodetector arrays may be arranged in the cross direction with a pitch spacing LP of, for example, 5 mm or less, in particular 4 mm or less, preferably 3 mm or less, more preferably 2 mm or less, and in some embodiments 1 mm or less.
The lower limit of the pitch interval may be determined according to the size of each photodetector unit in the cross direction (particularly the orthogonal direction), and for example, when adjacent photodetector arrays are in contact with each other, the size of the photodetector array corresponds to the lower limit of the pitch interval. Therefore, the lower limit of the pitch interval does not need to be particularly limited, and may be, for example, 0.3 mm or more, preferably 0.4 mm or more, more preferably 0.5 mm or more, and even more preferably 0.6 mm or more.
The pitch interval is the interval between two adjacent detector arrays, for example the interval between the center positions of the cross-direction (flow direction) dimensions of two adjacent detector arrays.

The overall length LA of each of the multiple photodetector arrays in the array direction in which the photodetector units are lined up may be, for example, 50 mm or less, preferably 40 mm or less, even more preferably 30 mm or less, particularly 20 mm or less, or even 15 mm or less.
The total length is, for example, 3 mm or more, preferably 5 mm or more, and may further be 7 mm or more.

The pitch spacing of the photodetector units in each photodetector array may be, for example, 0.05 mm or more, preferably 0.1 mm or more, and more preferably 0.2 mm or more.
The pitch interval may be, for example, 5 mm or less, preferably 3 mm or less, and more preferably 1 mm or less.

There may be dead zones between adjacent photodetector units in each photodetector array, but the width of the dead zones is preferably 100 μm or less, more preferably 80 μm or less, and even more preferably 70 μm or less. Preferably, it may be, for example, 30% or less, preferably 25% or less, more preferably 20% or less of the size of each photodetector unit in the array direction.

The size Ldb of each photodetector unit in the direction perpendicular to the array direction may be, for example, 0.3 mm or more, preferably 0.4 mm or more, more preferably 0.5 mm or more, and even 0.6 mm or more, in order to detect light more reliably.
From the viewpoint of miniaturization of the photodetector, the size Ldb may be, for example, 3 mm or less, preferably 2 mm or less, and more preferably 1.5 mm or less.
The size Lda of each photodetector unit in a direction parallel to the array direction may be, for example, 0.3 mm or more, preferably 0.4 mm or more, more preferably 0.5 mm or more, or even 0.6 mm or more, in order to detect light more reliably.
From the viewpoint of miniaturization of the photodetector, the size Lda may be, for example, 3 mm or less, preferably 2 mm or less, and more preferably 1.5 mm or less.

The light detection device may comprise a photocathode, i.e. each light detector unit may have a photocathode.
The maximum quantum efficiency of photoelectric conversion by the photocathode may be, for example, 5% or more, preferably 10% or more, and more preferably 15% or more.
Furthermore, the upper limit of the maximum quantum efficiency does not need to be set in particular, but may be, for example, 60% or less, 50% or less, or 40% or less.

The cathode lumen sensitivity of the photocathode may be, for example, 100 μA/lm or more, preferably 200 μA/lm or more, more preferably 300 μA/lm or more, and even more preferably 400 μA/lm or more.
The upper limit of the cathode lumen sensitivity of the photocathode is not particularly limited, but may be, for example, 1000 μA/lm or less.

In the case where the photodetection device includes a photodetector array in which photomultiplier units are arranged in a row, the current multiplication factor of the dynode of each photomultiplier unit may be, for example, 10 ⁴ or more, preferably 10 ⁵ or more, more preferably 0.5 × 10 ⁶ or more, and even more preferably 10 ⁶ or more.
The upper limit of the current multiplication factor is not particularly limited, but may be, for example, 10 ¹² or less, 10 ¹⁰ or less, or 10 ⁸ or less.

When the photodetector device includes a photodetector array in which photomultiplier units are arranged in a row, the dark current of the dynode of each photomultiplier unit is, for example, 5 nA or less, preferably 4 nA or less, and more preferably 3 nA or less per photomultiplier unit. It is desirable for the dark current to be as small as possible, and the lower limit does not need to be particularly limited, but it may be, for example, 0 nA or more per photomultiplier unit.

Furthermore, the dynodes of each photodetector unit may be configured so that gain correction can be performed independently of each other.
The lower limit of the ratio between the adjustable gains of each element in the array may be, for example, 1:1, 10:1, or even 100:1 or more, while the upper limit of the ratio is at least 100:1, preferably 1000:1, or even 10000:1.
This ratio is used to correct the variation in gain and sensitivity of the element itself, and to correct so that the same output is obtained when the same amount of light is input. Also, if there is a wavelength region in which the spectral light obtained from the sample is always dark, a correction may be made to increase the gain of the element corresponding to that wavelength region.

Each photodetector device may have an output circuit for outputting an electrical signal, the output circuit being configured, for example, such that the maximum output signal voltage of each photodetector unit is 0.01 V or more, preferably 0.03 V or more, more preferably 0.05 V or more, on a time average.
The output circuit may be configured so that the maximum output signal voltage of each photodetector unit is, on a time average, for example, 10 V or less, preferably 1 V or less.

The bandwidth of the output circuit may be, for example, DC to 5 MHz, preferably DC to 4 MHz, more preferably DC to 3.5 MHz, and in some embodiments DC to 3 MHz, or DC to 2.5 MHz, or DC to 2 MHz.

The current-voltage conversion characteristic of the output circuit may be, for example, 0.001 V/μA or more, and preferably 0.005 V/μA or more.
The current-voltage conversion characteristic of the output circuit may be, for example, 10 V/μA or less, preferably 1 V/μA or less.

The output circuit may have, for example, a low pass filter to reduce ripple noise, or may have other circuits or processes known in the art to reduce the ripple noise.

With regard to the output circuit, the crosstalk between each photodetector unit may be, for example, 3% or less, preferably 2% or less, and more preferably 1.5% or less. The value of the crosstalk is a ratio in which the signal output of the light incident element when light is incident only on a specific element is the denominator, and the signal output of the adjacent element is the numerator.

(3) Relationship with the light irradiation part

In a preferred embodiment, the flow cytometer according to the present disclosure may have a light irradiation unit that irradiates the bioparticles flowing through the flow path with light at multiple light irradiation positions along the flow direction of the flow path. Since the above-mentioned light detection device has multiple photodetector arrays, by using it in combination with a light irradiation unit that irradiates the bioparticles with light at multiple positions in the flow path, it is possible to realize a miniaturized flow cytometer and perform detailed bioparticle analysis based on the light generated by the light irradiation at each position. In other words, the flow cytometer according to the present disclosure may have a light irradiation unit including two or more laser light sources that are irradiated with light along different axes.
The light irradiation unit that irradiates light at a plurality of light irradiation positions may be configured to irradiate each of the plurality of light irradiation positions with light having a different wavelength. The wavelength of the irradiated light may be, for example, 200 nm to 1000 nm, and in particular, 300 nm to 900 nm. The light irradiation unit may have a plurality of laser light sources that emit laser light having a center wavelength within this wavelength range. Each of the laser lights emitted from the plurality of laser light sources is irradiated to each of the plurality of light irradiation positions.

In some embodiments, the flow cytometer according to the present disclosure may have a light irradiation unit that irradiates the bioparticles flowing through the flow path with light at one light irradiation position in the flow path. The above-mentioned light detection device may be incorporated into the flow cytometer in combination with the light irradiation unit. That is, the flow cytometer according to the present disclosure may include two or more laser light sources that are coaxially irradiated. Regarding the wavelength of the irradiated light, the explanation in the case of different axial irradiation applies.
In this embodiment, the two or more laser light sources are combined by, for example, a predetermined optical system and irradiated onto the one light irradiation position. The predetermined optical system may include, for example, one or more half mirrors and/or one or more dichroic mirrors, and can be appropriately designed by a person skilled in the art.

In a particularly preferred embodiment, a flow cytometer according to the present disclosure has a light irradiation unit that irradiates bioparticles flowing through the flow path with light at a plurality of light irradiation positions along the flow direction of the flow path, and may be further configured to detect light resulting from light irradiation at two or more of the plurality of light irradiation positions by a single light detection device, and may be particularly configured to detect light resulting from light irradiation at all of the plurality of light irradiation positions by a single light detection device.
As a result, as described above, it is possible to reduce the number of optical elements such as the photodetector side light guiding optical system, the diffraction grating, and the telecentric focusing lens, and it is possible to reduce the size of the flow cytometer.

The photodetector arrays of the photodetector device may be associated with the light sources (particularly laser light sources) of the light irradiation unit, as will be described below with reference to FIG.
In the figure, three light irradiation positions S1, S2, and S3 are shown. Laser beams L1, L2, and L3 are irradiated to these light irradiation positions, respectively. That is, the light irradiation unit is configured to irradiate the laser beams L1, L2, and L3 to the positions S1, S2, and S3, respectively. The laser beams L1, L2, and L3 may be beams having different wavelengths. These three light irradiation positions may be observed through one objective lens. In addition, all of the light generated by the light irradiation at these three light irradiation positions may be detected by one photodetector.
In this manner, the flow cytometer of the present disclosure may be configured such that light generated by light irradiation at multiple light irradiation positions is detected by a single light detection device.

The bioparticle P flows through the flow path C and is first irradiated with the laser beam L1, then with the laser beam L2, and finally with the laser beam L3. Each light irradiation causes light (e.g., fluorescent light and/or scattered light) to be generated from the bioparticle.
Also, the light detection device that detects the light generated by the light irradiation at these positions may be configured to have three detector arrays, for example, as shown in FIG. 2 or FIG. 3. The light detection device has detector arrays 282-1, 282-2, and 282-3. The detector array 282-1 may be associated with the laser light L1, and similarly, the detector array 282-2 may be associated with the laser light L2, and the detector array 282-3 may be associated with the laser light L3. More specifically, the detector array 282-1 detects light generated by the light irradiation of the particles with the laser light L1, the detector array 282-2 detects light generated by the light irradiation of the particles with the laser light L2, and the detector array 282-3 detects light generated by the light irradiation of the particles with the laser light L3. In this way, the light irradiation positions and the detector arrays may be associated in advance.
That is, the multiple light irradiation positions may be aligned along the flow direction of the particles, and the multiple detector arrays in the light detection device may be aligned to correspond to the multiple light irradiation positions. The order of the multiple detector arrays may be the same as the order of the light irradiation positions at which light irradiation that generates light detected by each of the multiple detector arrays is performed. That is, the multiple detector arrays may be aligned to correspond to the flow direction of the particles.

(4) Modified examples of optical detection devices

(4-1) Change of position

The light detection device described in (2) above has multiple light detector arrays. Each light detector array may be configured so that its position can be changed. An example of changing the position of a light detector array is described below.

(4-1-1) Changing the Position of the Photodetector Array in the Flow Direction In one embodiment, one or more of the multiple photodetector arrays may be configured so that the positions of the arrays in the arrangement direction can be changed independently of each other. That is, the spacing between the arrays may be configured so that it can be adjusted. This will be described with reference to FIG. 6.
The figure shows three detector arrays A1 to A3, one or more of which may be configured to be movable along an array arrangement direction DB.
For example, as shown in the figure, among the three arrays, only array A2 may be configured to be able to change its position, and arrays A1 and A3 may be configured to be unable to change their positions, i.e., array A2 may be moved closer to array A3, or may be moved closer to array A1.
Two of the three arrays may be configured to be able to change their positions. For example, the position of array A2 may be fixed, and the positions of arrays A1 and A3 may be changeable. Arrays A1 and A3 may be configured to be able to move along the array arrangement direction DB. Alternatively, array A1 may be configured to be fixed and arrays A2 and A3 may be configured to be able to move along the array arrangement direction DB, or array A3 may be configured to be fixed and arrays A1 and A2 may be configured to be able to move along the array arrangement direction DB.
All three arrays may be configured so that their positions can be changed, that is, all of the arrays A1 to A3 may be configured so that they can be moved along the array direction DB.
For the sake of simplicity, the above description has been given with respect to an optical detection device having three detector arrays; however, in the case of an optical detection device having four or more detector arrays, one or more of the detector arrays may be configured so that their positions can be changed in a similar manner.

By adjusting the array spacing in this way, appropriate array spacing can be achieved depending on the magnification of the flow path side optical system or the detector side optical system or the configuration or state of the flow path side optical system or the detector side optical system. For example, depending on the optical components of the flow path side optical system or the detector side optical system, it may be difficult for the light generated by light irradiation to reach the light detection device while reflecting the spacing of the light irradiation positions. In addition, the position of the light irradiation position in the flow direction may shift. In these cases, more appropriate light detection is possible by adjusting the array spacing as described above.

(4-1-2) Changing the Position of the Photodetector Array in the Array Direction In another embodiment, one or more of the multiple photodetector arrays may be configured so that the positions of the photodetector units in the array direction can be changed independently of one another. This will be described with reference to FIG.
The figure shows three detector arrays A1 to A3. One or more of these may be configured to be movable along a direction DA in which the photodetector units are lined up (detector unit array direction).
For example, among the three arrays, only the array A2 may be configured to be able to change its position, and the arrays A1 and A3 may be configured to be unable to change their positions, i.e., the array A2 may be moved along the detector unit array direction, for example, to the left or right in the figure.
Two of the three arrays may be configured so that their positions can be altered, or all three arrays may be configured so that their positions can be altered.
For the sake of simplicity, the above description has been given with respect to an optical detection device having three detector arrays; however, in the case of an optical detection device having four or more detector arrays, one or more of the detector arrays may be configured so that their positions can be changed in a similar manner.

By adjusting the position of the detector units in the array in this way, it is possible to efficiently detect the light generated by the light irradiation. For example, by adjusting the position according to the position in the flow channel through which the particles flow, more appropriate light detection is possible. Furthermore, when the wavelength of light to be detected is preset for each detector unit, the desired light can be detected more efficiently by changing the position.

For example, when fluorescence is split into wavelengths by a spectroscopic optical system, the light of each wavelength after splitting is arranged continuously from short wavelength light to long wavelength light along the array direction of the detector array. Here, the fluorescence usually has a wavelength longer than the excitation light wavelength or the excitation light. Therefore, when the position in the array direction remains fixed, some of the photodetector elements of the photodetector array will be present at the position where the fluorescence of the non-existent wavelength reaches, even though there is no fluorescence of a wavelength shorter than the excitation light in one detector array. The part of the photodetector elements may not be effectively used in the light detection. Therefore, by moving the position of the photodetector array in the array direction, the number of photodetector elements that are not effectively used in the light detection can be reduced.
For example, as shown on the left in Fig. 8, the photodetector array A2 is arranged from the position (Short) where the light on the short wavelength side reaches to the position (Long) where the light on the long wavelength side reaches. Here, when the wavelength of the excitation light that caused the fluorescence detected by the photodetector array A2 is the light of the wavelength at the position indicated by Lex, there is no fluorescence on the shorter wavelength side than Lex. Therefore, as shown on the right in the same figure, the position of the photodetector array A2 is moved to the long wavelength side. This makes it possible to reduce the photodetector elements that are not effectively used in detecting the fluorescence.

(4-1-3) Changing the Position of the Photodetector Array in Both Directions In yet another embodiment, one or more of the photodetector arrays may be configured to be able to change their positions in the array arrangement direction and in the direction in which the photodetector units are aligned, independently of one another. These changes in position are as described above with reference to Figures 6 and 7.

To change the position of the photodetector array as described above, the photodetector device may have an array position adjustment unit. The array position adjustment unit may be configured to adjust the array position using an electrical power source, such as a piezoelectric actuator or a motor and a screw feed mechanism, or may be configured to move the array position using a tool such as a screwdriver and then fix it with a screw after adjustment. The position of the photodetector array can be controlled by the array position adjustment unit. The drive of the array position adjustment unit may be controlled by an information processing unit described later.

(4-2) Modified photodetector array

3 described in (2) above, each of the three photodetector arrays has 10 photodetector elements. The number of photodetector elements in the photodetector arrays may be the same as in the figure, but may be different between two or more photodetector arrays. For example, the photodetector device 410 shown in FIG. 9 has three photodetector arrays A11, A12, and A13. The number of photodetector elements in the photodetector array A11 is 10, and the number of photodetector elements in the photodetector arrays A12 and A13 is 12 and 14, respectively. In this way, the multiple photodetector arrays in the photodetector device according to the present disclosure may have different numbers of photodetector elements. For example, the number of photodetector elements in one or more of the multiple photodetector arrays in the photodetector device may be different from the multiple photodetector arrays in the photodetector device of the other photodetector arrays.

In FIG. 3 described in (2) above, the positions of the three photodetector arrays in the array direction DA are the same. And, as described in (4-1) above, the positions of these photodetector arrays may be configured to be changeable in the array direction. In the present disclosure, the positions of the multiple detector arrays in the array direction DA may be different in advance. For example, the photodetector device 415 shown in FIG. 10 has four photodetector arrays A21, A22, A23, and A24. The positions of the photodetector arrays A21 and A22 in the array direction DA are the same. Also, the positions of the photodetector arrays A23 and A24 in the array direction DA are the same. On the other hand, the positions of the photodetector arrays A21 and A22 in the array direction DA are different from the positions of the photodetector arrays A23 and A24 in the array direction DA. In this way, the positions of the multiple photodetector arrays in the array direction DA of the photodetector device according to the present disclosure may be different from each other. For example, among a plurality of photodetector arrays included in the photodetection device, the position of one or more photodetector arrays in the array direction may be different from the position of the other photodetector arrays in the array direction.
The position of the photodetector array in the array direction may mean either one of the ends of each array in the array direction, or may mean the center position of each array in the array direction.

(4-3) Microlens array

The light detection device may further include a microlens array. The microlens array may be configured to focus light to be detected onto each light detector unit, thereby allowing light to be more efficiently guided into the light detector. The microlens array will be described with reference to FIG. 11.
As shown in the figure, the microlens array MLA may be provided so that light is focused on each of the photodetector elements PDE, i.e., the microlens array may be configured so that one microlens unit LU is present above one photodetector element PDE.
Each lens unit of the microlens array may have a curvature in the array direction DB, may have a curvature in the array arrangement direction DA (the direction from the front to the back of the paper in the figure), or may have a curvature in both of these directions.

(5) Use of optical fiber

The flow cytometer may have a propagation optical path that propagates the light generated by the light irradiation to the light detection device, and the propagation optical path may include one or more optical fibers. The number of optical fibers may be appropriately changed depending on, for example, the configuration of the optical fibers (particularly the number of cores) and/or the configuration of the light irradiation position.
For example, when a single optical fiber has one core (e.g., when an optical fiber having one core, one clad surrounding the core, and a coating layer surrounding the clad is used), the same number of optical fibers as the number of light irradiation positions may be used as the propagation optical path.
When a single optical fiber has multiple cores (for example, when an optical fiber having a clad with multiple cores and a coating layer surrounding the clad is used), a number of optical fibers fewer than the number of light irradiation positions may be used as the propagation optical path.

In one embodiment, the propagation path includes a plurality of optical fibers, which may preferably be bundled together, i.e. the propagation path may comprise an optical fiber bundle, each optical fiber having one core, but may also have multiple cores.
For example, the multiple optical fibers may be bundled so that the arrangement of the cores of each optical fiber is fixed at the light incident end (the end where light generated by irradiating a bioparticle with light is incident).
Furthermore, the plurality of optical fibers may be bundled so that the arrangement of the cores of each optical fiber is fixed at the light output end (the end that outputs light that has been input from the input end).
By bundling in this manner, the cores of the plurality of optical fibers can be arranged to form a linear row at the input end and/or the output end.

In another embodiment, the propagation path may include a single optical fiber, and multiple core-clad sets may be provided within the single optical fiber.
For example, the multiple core-clad sets may be fixed so that the arrangement of the multiple cores is fixed at the light input end.
Furthermore, the plurality of core-clad sets may be fixed at the light output end so that the arrangement of the plurality of cores is fixed.
The plurality of optical fibers may be bundled.
By fixing the arrangement of the cores in this manner, the multiple cores of the optical fiber can be arranged to form a linear row at the input end and/or the output end.

In yet another embodiment, the propagation optical path includes a single optical fiber, and multiple cores may be provided in the single optical fiber, particularly multiple cores may be provided in a single clad, such that the arrangement of the multiple cores is fixed at the light input end, and also at the light output end.
By fixing the arrangement of the cores in this manner, the multiple cores of the optical fiber can be arranged to form a linear row at the input end and/or the output end.

An example of the optical fiber configuration will be described later with reference to Figures 19A to 19H. In addition, an example of using an optical fiber as an example of a propagation optical path that propagates light generated by light irradiation to a light detection device in the flow cytometer has been shown, but instead of an optical fiber, any means that can be used as a light propagation optical path may be used as the propagation optical path, such as a rod integrator that propagates incident light by total internal reflection. In this case, other than using any light propagation means instead of an optical fiber, the configuration described in this specification can be preferably used.

An example of the configuration of a flow cytometer according to the present disclosure having a propagation optical path including an optical fiber will be described with reference to FIG. 12. The flow cytometer 400 shown in the figure is the same as the flow cytometer 200 shown in FIG. 2, except that an optical fiber bundle 440 is provided instead of the field stop 240.

As shown in FIG. 12 , the optical fiber bundle 440 may be provided on the optical path between the flow cell 210 and the spectroscopic optical system 260, for example, on the optical path between the flow path side light-guiding optical system 230 and the detector side light-guiding optical system 250.
The optical fiber bundle 440 may be a bundle of optical fibers corresponding to the number of light irradiation positions, and three optical fibers are bundled in the figure. The optical fiber bundle 440 may have a structure as shown in Fig. 19A described below, for example.

As shown in the figure, three optical fiber cores CI1, CI2, and CI3 are present at the light-input end IE of the optical fiber bundle 440 (note that the cladding and coating layer are omitted in the figure). The optical fiber core CI1 is a core into which light generated by irradiating a bioparticle with light at the light irradiation position S1 enters. Similarly, the optical fiber cores CI2 and CI3 are cores into which light generated by irradiating a bioparticle with light at the light irradiation position S2 enters and cores into which light generated by irradiating a bioparticle with light at the light irradiation position S3 enters, respectively.
At the end, the arrangement intervals of the three optical fiber cores CI1, CI2, and CI3 are fixed. The arrangement intervals may correspond to the intervals between the light irradiation positions S1, S2, and S3. For example, the arrangement interval of two optical fiber cores present at the light incident end may be set based on "the interval between two light irradiation positions at which light incident on the two optical fiber cores occurs" and "the magnification of the flow path side light guiding optical system". The magnification of the flow path side light guiding optical system may be an optical magnification determined by one or more optical elements (e.g., lenses, etc.) present between the flow path to be irradiated with light and the light incident end of the optical fiber bundle.
In this way, the arrangement of the optical fiber cores may be fixed at the light incident end, and in particular, the optical fiber cores may be arranged at the light incident end so as to correspond to the intervals between the light irradiation positions on the flow path. In this case, the intervals between the optical fiber cores at the light incident end may be set based on, for example, (the intervals between the light irradiation positions on the flow path) and (the magnification of the flow path side light guiding optical system), and may be, for example, an interval equivalent to "(the intervals between the light irradiation positions on the flow path) x (the magnification of the flow path side light guiding optical system)".

As shown in the figure, three optical fiber cores CO1, CO2, and CO3 are present at the light output end OE of the optical fiber bundle 440. The optical fiber core CO1 is a core that outputs light generated by light irradiation of a bioparticle at a light irradiation position S1. Similarly, the optical fiber cores CO2 and CO3 are cores that output light generated by light irradiation of a bioparticle at a light irradiation position S2 and a core that output light generated by light irradiation of a bioparticle at a light irradiation position S3, respectively.
At the end, the arrangement intervals of the three optical fiber cores CO1, CO2, and CO3 are fixed. The arrangement intervals may correspond to the intervals of the photodetector arrays 282-1 to 282-3 of the photodetector 280. For example, the arrangement interval of two optical fiber cores present at the light emission end may be set based on the "interval between two photodetector arrays assigned to detect light emitted by the two optical fiber cores" and the "magnification of the detector-side light guiding optical system". The interval between the photodetector arrays may mean the interval in the cross direction DB. In addition, the magnification of the detector-side light guiding optical system may be an optical magnification determined by one or more optical elements (e.g., lenses, etc.) present between the photodetector and the light emission end of the optical fiber bundle.
In this way, the arrangement of the optical fiber cores may be fixed at the light output end, and in particular, the optical fiber cores may be arranged at the light output end so as to correspond to the spacing of the photodetector array. In this case, the spacing of the optical fiber cores at the output end may be set based on, for example, the spacing of the photodetector array and the magnification of the detector-side optical system, and may be, for example, a spacing equivalent to "(spacing of the photodetector array) x (magnification of the detector-side optical system)".
The arrangement of the photodetector array corresponding to the light-emitting ends of the above-mentioned multiple optical fiber cores may be adjusted appropriately to correspond to the optical path of light from the light-emitting end of the optical fiber bundle 440 to the photodetector 280. Conversely, the arrangement of the light-emitting ends of the optical fiber cores may be adjusted to correspond to the arrangement of the photodetector array.
Here, the optical path of light from the light emitting end of the optical fiber bundle 440 to the light detection device 280 is determined by the detector side light guiding optical system 250, the spectroscopic optical system 260 and the telecentric focusing lens 270 used, or a combination of these, or the arrangement of these configurations.

A schematic example of an optical fiber bundle included in the flow cytometer of the present disclosure is shown in Fig. 13. The optical fiber bundle 450 shown in the figure is a bundle of four optical fibers. Note that in the figure, the optical fiber bundle is shown branched into four fibers near the ends IE and OE, but this is only shown as branched on the drawing to explain the spacing between the four cores, and an optical fiber bundle that is actually used does not need to have such branches, and may be configured as a single linear structure as shown in Fig. 12.
At both the light input end IE and the light output end OE of the bundle, the positional relationship of the four optical fibers is fixed, i.e., the arrangement (spacing) of the four optical fiber cores at these ends is fixed. As shown in the figure, at the light input end IE, the multiple cores may be arranged in a straight line. At the light output end OE, the multiple cores may also be arranged in a straight line.
In addition, the distance between the cores of two optical fibers described above may be the linear distance between the cores CI1 and CI2 at the light input end in the figure, and is the distance indicated by the arrow Lci in the figure. The same applies to the distances between the other two cores.
For example, the distance between the cores CO1 and CO2 at the light input end in the figure may be the straight-line distance between the cores CO1 and CO2, which is the distance indicated by the arrow Lco in the figure. The same is true for the interval between the other two cores.
Furthermore, the distance Lci and the distance Lco do not necessarily have to be the same distance, that is, these distances may be appropriately adjusted according to the optical magnifications on the entrance side and exit side.

As described above, the flow cytometer of the present disclosure may have an optical fiber bundle. At both ends (the light input end and the light output end) of the optical fiber bundle, the arrangement of the cores of the optical fibers included in the optical fiber bundle may be fixed, and in particular, the arrangement intervals of the cores of the optical fibers may be fixed.
12 and 13, the number of cores is three and four, respectively, but it is clear that the number is not limited thereto. For example, the number of cores may be the same as the number of light irradiation positions (or the number of photodetector arrays in the photodetector device), and may be, for example, two or more.
Also, in some embodiments, the number of cores may be less than the number of light irradiation positions (or the number of photodetector arrays in a light detection device), in which case at least one optical fiber may be shared as an optical path by light generated by irradiation at two or more light irradiation positions.
In another embodiment, the number of cores may be greater than the number of light irradiation positions (or the number of photodetector arrays in the photodetection device). In this case, the optical fiber used as the propagation path of the light generated by the light irradiation of the bioparticles may be appropriately switched.
12 shows an example of a flow cytometer in which an optical fiber bundle is used, an unbundled optical fiber may be used instead of the optical fiber bundle. The optical fiber may be, for example, an optical fiber having multiple core-clad sets as described above, as described below, or an optical fiber having multiple cores in a single clad.
Even when such an optical fiber is used, as described above, the optical fiber cores may be arranged at the light input end so as to correspond to the intervals between the light irradiation positions on the flow path, and as described above, the optical fiber cores may be arranged at the light output end so as to correspond to the intervals between the photodetector arrays.

Examples of the configuration of optical fibers that can be used in the present disclosure are described below with reference to the drawings. As the optical fiber that forms the optical propagation path, any of the optical fiber bundles or optical fibers described in Examples 1 to 3 below may be used, and two or more of these may be used in combination.

(Example 1: Optical fiber bundle)
19A is a schematic cross-sectional view of an example of an optical fiber bundle. This drawing is a schematic cross-sectional view approximately perpendicular to the light traveling direction, and each component does not reflect its actual size.
The optical fiber bundle 700 shown in the figure is a bundle having three optical fibers 701. Each optical fiber 701 has a core 703, a cladding 704 surrounding the periphery of the core, and a coating layer 704 surrounding the periphery of the cladding. In other words, the core, the cladding, and the coating layer are stacked concentrically. The materials of the core, the cladding, and the coating layer may all be known materials used in the art.
As shown in the figure, the optical fiber bundle 700 has three optical fibers 701 arranged so that they appear lined up in a row in the cross section, and the arrangement is fixed by a fixing member 702. Note that the arrangement does not have to be fixed, and for example, the bundle does not have to be fixed in the middle (i.e., in the middle region other than the light input end and the light output end of the bundle). The fixing member 702 may be a known material used in this technical field, such as resin, rubber, or fiber.
In addition, although the optical fiber bundle 700 shown in Fig. 19A has three optical fibers, the number of optical fibers in the bundle is not limited to three, and may be two or more, three or more, or four or more, for example, a number corresponding to or greater than the number of photodetector arrays. Furthermore, in Fig. 19A, the bundle is configured such that three optical fibers appear in a row in the cross section of the optical fiber bundle, but the arrangement of the optical fibers is not limited to this. For example, as in the optical fiber bundle 800 shown in Fig. 19B, a larger number of optical fibers may be bundled, that is, they do not necessarily have to be arranged to form only one row as in Fig. 19A.

(Example 2: Optical fiber having multiple core-cladding sets)
19C is a schematic cross-sectional view of an example of an optical fiber. The optical fiber 710 shown in the figure has three core-clad sets 711. Each core-clad set refers to a set of a core 713 and a clad 714 surrounding the core (i.e., a structure consisting of these two elements). Furthermore, a coating layer 712 is provided so as to surround the three core-clad sets. The materials of the core, the clad, and the coating layer may all be known materials used in the art.
The optical fiber 710 shown in the figure has three core-clad sets 711 arranged so as to appear lined up in a row in the cross section, and this arrangement is fixed by a coating layer 712. Note that this arrangement does not have to be fixed, and for example, it does not have to be fixed in the middle of the bundle (i.e., in a middle region other than the light input end and light output end of the bundle).
Also, although the optical fiber 710 shown in Fig. 19C has three core-clad sets 711, the number of core-clad sets that the optical fiber has is not limited to three, and may be two or more, three or more, or four or more, for example, a number corresponding to or greater than the number of photodetector arrays. Furthermore, although the optical fiber in Fig. 19C is configured such that three core-clad sets appear lined up in a row in the optical fiber cross section, the arrangement of the core-clad sets is not limited to this. For example, as in the optical fiber bundle 810 shown in Fig. 19D, a plurality of core-clad sets may be bundled together, that is, they do not necessarily have to be arranged to form only one row as in Fig. 19C.

Fig. 19E is a schematic cross-sectional view of another example of a single optical fiber. The optical fiber 720 shown in this figure is the same as the optical fiber 710 shown in Fig. 19C, except that the positions of the three core-clad sets 711 are fixed by a fixing material (e.g., a resin or the like) 715. In the present disclosure, an optical fiber in which the arrangement of the multiple core-clad sets 711 is fixed by a fixing material in this manner may be used. A coating layer may be present around the fixing material, as in Fig. 19C. The fixing material may be a known material used in the art.
Also, the optical fiber 720 shown in Fig. 19E has three core-clad sets 711, but the number of core-clad sets in the optical fiber is not limited to three, and may be two or more, three or more, or four or more, for example, a number corresponding to or greater than the number of photodetector arrays. Also, in Fig. 19E, the optical fiber is configured such that three core-clad sets appear in a row in the optical fiber cross section, but the arrangement of the core-clad sets is not limited to this. For example, a plurality of optical fibers may be bundled together, as in the optical fiber bundle 820 shown in Fig. 19F, that is, they do not necessarily have to be arranged to form only one row as in Fig. 19E.
In one embodiment, the fixation with the fixation material shown in Fig. 19E may be performed, for example, only at the light output end and/or the light input end of the optical fiber, and fixation may not be performed in the intermediate region. That is, the optical fiber is fixed with the fixation material at the light output end and/or the light input end as shown in Fig. 19E or F, and fixation with the fixation material may not be performed in the intermediate region as shown in Fig. 19C or D.
In another embodiment, immobilization with the immobilization material shown in FIG. 19E may be performed over the entire optical fiber, including the light output end and/or the light input end of the optical fiber.

(Example 3: Optical fiber with multiple cores in the cladding)
19G is a schematic cross-sectional view of another example of an optical fiber. The optical fiber 730 shown in the figure has three cores 733. The three cores 733 are present in one cladding 734. A coating layer 732 is provided to surround the cladding. The materials of the core, the cladding, and the coating layer may all be known materials used in the art.
The optical fiber 730 shown in the figure has three cores 733 arranged in a row, and their arrangement is fixed by a cladding 734.
In addition, the optical fiber 730 shown in the figure has three cores 733, but the number of cores in the optical fiber is not limited to three, and may be two or more, three or more, or four or more, for example, a number corresponding to or greater than the number of photodetector arrays. In addition, in the figure, the optical fiber is configured so that three cores appear in a row in the optical fiber cross section, but the arrangement of the cores is not limited to this. For example, as in the optical fiber 830 shown in Figure 19H, multiple cores may be present in the cladding, that is, they do not necessarily have to be arranged to form only one row as in Figure 19G.

(6) Designing the light path using a spectroscopic optical system

An example of the design of the optical path of light through the spectroscopic optical system to the light detection device in the flow cytometer according to the present disclosure will be described with reference to FIG.
Fig. 14 is a schematic diagram of the optical path of light to a photodetector designed by a spectroscopic optical system. For example, in the configuration example of the flow cytometer shown in Fig. 2, the optical path can be applied as the optical path from the field stop 240 to the photodetector 280. Also, in the configuration example of the flow cytometer shown in Fig. 12, the optical path can be applied as the optical path from the light emission end of the optical fiber bundle 440 to the photodetector 280.

Light incident from the light input end X shown in FIG. 14, such as from the light output end of the field stop 240 or the optical fiber bundle 440, passes through the detector-side light-guiding optical system 250 and is adjusted to an arbitrary direction, such as parallel. The optical components constituting the detector-side light-guiding optical system 250 may suitably be optical components that can be used as the detector-side light-guiding optical system described in this specification. FIG. 14 shows an example in which an optical system consisting of two lenses is used, but this is not limiting and a person skilled in the art may design it as desired depending on the purpose.

The light that has been adjusted in a desired direction by the detector-side light-guiding optical system 250 is separated into wavelengths by the spectroscopic optical system 260. The optical components that make up the spectroscopic optical system 260 may suitably be optical components that can be used as spectroscopic optical systems described in this specification. In FIG. 14, an example is shown in which three prisms designed with an apex angle of 40 degrees are used, but this is not limiting and a person skilled in the art may design it as desired depending on the purpose.

The light dispersed by the dispersive optical system 260 reaches the telecentric focusing lens 270. The telecentric focusing lens 270 adjusts the traveling direction of the dispersed light to any direction, such as parallel, and causes it to reach the photodetector 280. The optical components constituting the telecentric focusing lens 270 may suitably be optical components that can be used as the telecentric focusing lens described in this specification. FIG. 14 shows an example in which an optical system consisting of two lenses is used, but this is not limiting and a person skilled in the art may design it as desired depending on the purpose.

In the example shown in FIG. 14, light generated by irradiating biological particles flowing through a flow channel with light at multiple light irradiation positions reaches the light detection device 280 via the same detector-side light guiding optical system 250, spectroscopic optical system 260, and telecentric focusing lens 270. In other words, a flow cytometer according to the present disclosure can be designed in a form in which the number of detector-side light guiding optical systems 250, spectroscopic optical systems 260, and telecentric focusing lenses 270 is fewer than the number of light irradiation positions.

Figure 15 shows the incident surface when light that has traveled along the optical path to the light detection device shown in the example of Figure 14, for example, enters the light detection device.

When the light generated by irradiating biological particles flowing through a flow path with light at multiple light irradiation positions is dispersed by a spectroscopic optical system and then imaged on the incident surface of a light detection device, the position on the incident surface where the spectrum of light corresponding to the light irradiation position is output may shift due to aberrations caused by optical components, etc.
In addition, the light constituting the spectrum output on the incident surface by the above-mentioned splitting has a different output width for each wavelength. In general, the output width of light with a short wavelength is wider, and the output width of light with a long wavelength is narrower. Therefore, the amount of light per unit area output on the incident surface of the short wavelength light is relatively smaller than that of light with a long wavelength.

In the example shown in Fig. 15, four light spectra Y1 to Y4 are output on the incident surface of the light detection device in correspondence with four light irradiation positions. In Fig. 15, it can be seen that the positions at which the four light spectra Y1 to Y4 are output are shifted along the array direction DA of the array arranged to match the output positions of these spectra. Accordingly, it can be seen that the positions at which light of the same wavelength is output are also shifted along the array direction DA.
Furthermore, in FIG. 15, it can be seen that, for each of the light components Y1 to Y4, the width of the light having a short wavelength is wider, and the width of the light having a long wavelength is narrower.

The amount and direction of deviation of the position on the incident surface where the spectrum of light corresponding to the light irradiation position is output are determined by the detector-side light guiding optical system 250, the spectroscopic optical system 260, and the telecentric condenser lens 270 used in the flow cytometer, or a combination of these, or the arrangement of these configurations and the optical path through these optical components. Conversely, the arrangement and optical path of the optical components may be adjusted according to the position where the spectrum is to be output. For example, FIG. 15 shows the incident surface when light passing through the optical path to the photodetector shown in the example of FIG. 14 using a prism as the spectroscopic optical system is incident on the photodetector, but when a diffraction grating is used instead of a prism as the spectroscopic optical system, the effect on the deviation of the position where the spectrum is output is generally smaller than when a prism is used. Therefore, the position where the spectrum is output on the incident surface may be adjusted by considering the characteristics of the optical components used and adjusting the optical components used and their arrangement.
In addition, the width of the light for each wavelength constituting the output spectrum is determined by the light separation power of the spectroscopic optical system used. Based on this, the area of the light receiving surface of the photodetector elements constituting the photodetector array may be adjusted to match the width of the light for each wavelength output, or the sensitivity may be adjusted to match the amount of light for each wavelength output.

In the example shown in Fig. 15, the spectra output on the incident surface are output at a predetermined interval along a cross direction DB that crosses the array direction DA. The interval at which the spectra are output corresponds to the interval of light incident at the light incident end X shown in Fig. 14. For example, when light is incident on the incident end X at an interval corresponding to the interval of the light irradiation positions on the bioparticles flowing through the flow channel, the interval of the spectra output on the incident surface corresponds to the interval of the light irradiation positions.
Therefore, the spacing of the spectra output on the incident surface can also be adjusted, for example, by the spacing of the light irradiation positions on the biological particles flowing through the flow path, or the position of the optical fiber core at the light output end of the optical bundle fiber.
Here, the "corresponding interval" is not limited to the same interval, but includes the interval multiplied by a certain factor.

Figure 16 is a schematic diagram showing an example of a light detection device having multiple light detector arrays corresponding to the positions of the spectrum of light output to the incident surface of the light detection device shown in the example of Figure 15.

That is, the four photodetector arrays A1 to A4 of the photodetector device shown in FIG. 16 are arranged corresponding to the positions where the four light spectra Y1 to Y4 shown in the example of FIG. 15 are output. Note that FIG. 16 shows an example that matches the incidence example shown in FIG. 15, but is not limited to this, and the number of photodetector arrays and the arrangement of the photodetector arrays can be adjusted according to the number of spectra output to the incident surface of the photodetector device and their output positions. Conversely, the number of spectra output to the incident surface of the photodetector device and their output positions can be adjusted according to the number of photodetector arrays of the photodetector device and the arrangement of the photodetector arrays.

Also, FIG. 16 shows an example of a photodetection device having a photodetector array with multiple photodetector elements whose light receiving surface area is not constant. In this case, by adjusting the area of the light receiving surface of the photodetector elements in the photodetector array to an area according to the width at which light for each wavelength to be detected is output or the amount of light, it is possible to suppress variations in the detection sensitivity of the photodetector array for the wavelength of light. In addition to the above, for example, by adjusting the area of the light receiving surface of the element according to the APD sensitivity for each wavelength region of the photodetector element used, it is also possible to suppress variations in the detection sensitivity of the photodetector array for the wavelength of light.

As shown in FIG. 16, the multiple photodetector arrays in the photodetector device are made up of a combination of identical photodetector elements, and the photodetector arrays are arranged to correspond to the positions of the spectrum of the output light, thereby making it possible to avoid variations in detection sensitivity for each wavelength.

(7) Other configuration examples (using multiple photodetectors)

2 has one photodetector. The number of photodetectors included in the flow cytometer of the present disclosure is not limited to one, and may be two or more. That is, in one embodiment, the flow cytometer of the present disclosure may include two or more photodetectors, and at least one of the two or more photodetectors may have a plurality of photodetector arrays.
Having two or more photodetector devices contributes to the effective use of the photodetector elements of each photodetector device, and also contributes to the detection of light that has been more finely dispersed. For example, when detecting fluorescence generated by irradiating a biological particle with excitation light of a specific wavelength, a notch filter that cuts the excitation light may be provided on the optical path of the light guide optical system (e.g., the detector-side light guide optical system) to prevent the excitation light from being detected. The notch filter does not transmit light near the wavelength of the excitation light. Therefore, the notch filter has the advantage that only fluorescence is detected, but the photodetector element assigned to detect light having the wavelength of the excitation light is not utilized. Therefore, a flow cytometer may be configured to incorporate multiple photodetector devices, with each photodetector device detecting light in a different wavelength range.
This embodiment is described below with reference to FIG.

The flow cytometer 500 shown in FIG. 17 has the same configuration as the flow cytometer shown in FIG. 2, except that the detector-side light-guiding optical system 250, the spectroscopic optical system 260, the telecentric focusing lens 270, and the photodetector 280 have been changed to the detector-side light-guiding optical system 550 (551 to 554), the spectroscopic optical system 560 (560-1 to 560-3), the telecentric focusing lens 570 (570-1 to 570-3), and the photodetector 580 (580-1 to 580-3), respectively.

As described in (1) above, each of the light detection devices 580-1, 580-2, and 580-3 has a plurality of light detector arrays arranged at predetermined intervals along the flow direction. The flow cytometer 500 is configured so that these three light detection devices each detect light in a different wavelength range.
As an example, assume that excitation light with a wavelength of 390 nm, excitation light with a wavelength of 540 nm, and excitation light with a wavelength of 690 nm are irradiated onto a biological particle at three irradiation positions, and light with a wavelength of 400 nm to 850 nm is detected.
In this case, each photodetector is assigned such that photodetector 580-1 detects light with wavelengths of 400 nm to 530 nm, photodetector 580-2 detects light with wavelengths of 550 nm to 680 nm, and photodetector 580-3 detects light with wavelengths of 700 nm to 850 nm. Also, light with wavelengths of 530 nm to 550 nm and light with wavelengths of 680 nm to 700 nm are cut by notch filters, respectively.

The light that passes through the field stop 240 is separated into light of the three wavelength ranges by the detector-side light-guiding optical system 550. The light-guiding optical system 550 may be configured, for example, as follows, but the configuration may be changed as appropriate depending on, for example, the number of photodetectors or the wavelength range detected by each photodetector.

The light that passes through the field stop 240 passes through a lens 551 (e.g., a collimator lens) and then reaches the dichroic mirror 552.

The dichroic mirror 552 has the optical property of reflecting light with a wavelength of 550 nm or less and transmitting light with a wavelength of more than 550 nm, so that the fluorescence with a wavelength of 550 nm or less reaches the spectroscopic optical system 560-1 (a transmission type diffraction grating in the figure).
The light transmitted through the dichroic mirror 552 (i.e., light with a wavelength longer than 550 nm) reaches the dichroic mirror 553. The dichroic mirror 553 has the optical property of reflecting light with a wavelength of 700 nm or less and transmitting light with a wavelength longer than 700 nm. As a result, the fluorescence with a wavelength longer than 550 nm and shorter than 700 nm reaches the spectroscopic optical system 560-2 (transmissive diffraction grating).
The light transmitted through the dichroic mirror 553 (i.e., light with a wavelength longer than 700 nm) reaches the mirror 554. The mirror 554 has the optical property of reflecting light with a wavelength of 850 nm or less. As a result, the fluorescence with a wavelength longer than 700 nm and shorter than 850 nm reaches the spectroscopic optical system 560-3 (transmissive diffraction grating).
The detector-side light-guiding optical system 550 may further include one or more notch filters (not shown) that cut off the excitation light. The one or more notch filters may be appropriately disposed on the optical path of the optical system.

The spectroscopic optical system 560-1 separates the light of wavelengths between 400 nm and 550 nm that arrives. The separated light is collimated by the telecentric condenser lens 570-1 and reaches the photodetector device 580-1. The photodetector device 580-1 has a plurality of photodetector arrays. Each photodetector array has photodetector elements arranged in a row. Each photodetector array is assigned to detect light of 400 nm to 550 nm. More specifically, the photodetector elements at one end of the array are assigned to detect light of a wavelength of about 400 nm, and the photodetector elements at the other end of the array are assigned to detect light of a wavelength of 550 nm. The photodetector elements between the two ends detect the separated light of wavelengths between 400 nm and 550 nm.

The spectroscopic optical system 560-2 separates the light of wavelengths between 550 nm and 700 nm that arrives. The separated light is collimated by the telecentric focusing lens 570-2 and reaches the photodetector device 580-2. The photodetector device 580-2 has a plurality of photodetector arrays. Each photodetector array has a row of photodetector elements. Each photodetector array is assigned to detect light of 550 nm to 700 nm. More specifically, the photodetector elements at one end of the array are assigned to detect light of a wavelength of about 550 nm, and the photodetector elements at the other end of the array are assigned to detect light of a wavelength of 700 nm. The photodetector elements between the two ends detect the separated light of wavelengths between 550 nm and 700 nm.

The spectroscopic optical system 560-3 separates the light of wavelengths between 700 nm and 850 nm that arrives. The separated light is collimated by the telecentric condenser lens 570-3 and reaches the photodetector device 580-3. The photodetector device 580-3 has a plurality of photodetector arrays. Each photodetector array has photodetector elements arranged in a row. Each photodetector array is assigned to detect light of 700 nm to 850 nm. More specifically, the photodetector elements at one end of the array are assigned to detect light of a wavelength of about 700 nm, and the photodetector elements at the other end of the array are assigned to detect light of a wavelength of 850 nm. The photodetector elements between the two ends detect the separated light of wavelengths between 700 nm and 850 nm.

As described above, the detector-side light-guiding optical system 550 splits the light into multiple wavelength ranges and causes it to reach each of the multiple light detection devices. The photodetector array of each of the multiple light detection devices is configured to detect the light in the wavelength range that reaches it using the entire array. This makes effective use of the photodetector array. In addition, more detailed analysis is possible.

(8) An embodiment without an objective lens

A typical flow cytometer is provided with an objective lens through which light generated by irradiating biological particles flowing through a flow path passes. The objective lens is provided near the flow path, for example, immediately adjacent to a flow cell or a cuvette.
In some embodiments, the flow cytometer according to the present disclosure may not have the objective lens. In this embodiment, the light detection device may be disposed on the flow path, i.e., the light generated by the light irradiation may be detected by the light detection device without passing through an objective lens. In addition, in the flow cytometer configured in this manner, image data of the bioparticles may be acquired by the light detection device.

(9) Example of flow cytometer configuration

A flow cytometer according to the present disclosure may include a light irradiation unit, a detection unit, and an information processing unit. Furthermore, a flow cytometer according to the present disclosure may further include a fractionation unit. The light irradiation unit, detection unit, information processing unit, and fractionation unit may be configured as described below with respect to the biological sample analyzer. A light detection device according to the present disclosure may be mounted on the flow cytometer as a component of the detection unit.
Furthermore, the biological particles to be irradiated with light by a flow cytometer according to the present disclosure may be prepared as a biological sample as described below. Furthermore, a flow path through which the biological particles flow may be configured as described below with respect to a biological sample analyzer.
Furthermore, the flow cytometer according to the present disclosure may be configured not only as a flow cytometer that only analyzes bioparticles, but also as a flow cytometer (also called a cell sorter) that sorts predetermined bioparticles based on the analysis results. The cell sorter may be configured to perform sorting processing in an open space, or may be configured to perform sorting processing in a closed space.
In addition, if there is a discrepancy between the contents explained in (1) to (8) above and the contents explained in (9) of this section, the contents explained in (1) to (8) above shall take precedence.

An example of the configuration of the biological sample analyzer of the present disclosure is shown in FIG. 18. The biological sample analyzer 6100 shown in FIG. 18 includes a light irradiation unit 6101 that irradiates light onto the biological sample S flowing through a flow path C, a detection unit 6102 that detects light generated by irradiating the biological sample S with light, and an information processing unit 6103 that processes information related to the light detected by the detection unit. Examples of the biological sample analyzer 6100 include a flow cytometer and an imaging cytometer. The biological sample analyzer 6100 may include a fractionation unit 6104 that separates specific biological particles P from within the biological sample. An example of the biological sample analyzer 6100 that includes the fractionation unit is a cell sorter.

(Biological samples)
The biological sample S may be a liquid sample containing biological particles. The biological particles are, for example, cells or non-cellular biological particles. The cells may be living cells, and more specific examples include blood cells such as red blood cells and white blood cells, and reproductive cells such as sperm and fertilized eggs. The cells may be directly collected from a specimen such as whole blood, or may be cultured cells obtained after culture. Examples of the non-cellular biological particles include extracellular vesicles, particularly exosomes and microvesicles. The biological particles may be labeled with one or more labeling substances (e.g., dyes (particularly fluorescent dyes) and fluorescent dye-labeled antibodies, etc.). Note that the biological sample analyzer of the present disclosure may analyze particles other than biological particles, and beads, etc. may be analyzed for calibration, etc.

(Flow path)
The flow channel C is configured to allow the biological sample S to flow. In particular, the flow channel C can be configured to form a flow in which biological particles contained in the biological sample are arranged in a substantially straight line. The flow channel structure including the flow channel C may be designed to form a laminar flow. In particular, the flow channel structure is designed to form a laminar flow in which the flow of the biological sample (sample flow) is surrounded by the flow of the sheath liquid. The design of the flow channel structure may be appropriately selected by a person skilled in the art, and a known design may be adopted. The flow channel C may be formed in a flow channel structure such as a microchip (a chip having a flow channel on the order of micrometers) or a flow cell. The width of the flow channel C may be 1 mm or less, and in particular, 10 μm or more and 1 mm or less. The flow channel C and the flow channel structure including the flow channel C may be formed from a material such as plastic or glass.

The biological sample analyzer of the present disclosure is configured so that the biological sample flowing through the flow path C, particularly the biological particles in the biological sample, is irradiated with light from the light irradiating unit 6101. The biological sample analyzer of the present disclosure may be configured so that the interrogation point of light on the biological sample is in the flow path structure in which the flow path C is formed, or the interrogation point of light may be configured so that it is outside the flow path structure. An example of the former is a configuration in which the light is irradiated to the flow path C in a microchip or flow cell. In the latter, the light may be irradiated to the biological particles after they have left the flow path structure (particularly the nozzle portion thereof), and an example of this is a jet-in-air type flow cytometer.

(Light Irradiation Unit)
The light irradiation unit 6101 includes a light source unit that emits light and a light guide optical system that guides the light to an irradiation point. The light source unit includes one or more light sources. The type of light source is, for example, a laser light source or an LED. The wavelength of the light emitted from each light source may be any of ultraviolet light, visible light, and infrared light. The light guide optical system includes optical components such as a beam splitter group, a mirror group, or an optical fiber. The light guide optical system may also include a lens group for collecting light, including, for example, an objective lens. There may be one or more irradiation points where the biological sample and the light intersect. The light irradiation unit 6101 may be configured to collect light irradiated from one or more different light sources to one irradiation point.

(Detection unit)
The detection unit 6102 includes at least one photodetector that detects light generated by irradiating the bioparticles with light. The light to be detected is, for example, fluorescence or scattered light (for example, one or more of forward scattered light, back scattered light, and side scattered light). Each photodetector includes one or more light receiving elements, and has, for example, a light receiving element array. Each photodetector may include, as a light receiving element, one or more PMTs (photomultiplier tubes) and/or photodiodes such as APDs and MPPCs. The photodetector includes, for example, a PMT array in which a plurality of PMTs are arranged in a one-dimensional direction. The detection unit 6102 may also include an imaging element such as a CCD or CMOS. The detection unit 6102 may acquire an image of the bioparticle (for example, a bright field image, a dark field image, and a fluorescent image) using the imaging element.

The detection unit 6102 includes a detection optical system that allows light of a predetermined detection wavelength to reach a corresponding photodetector. The detection optical system includes a spectroscopic section such as a prism or a diffraction grating, or a wavelength separation section such as a dichroic mirror or an optical filter. The detection optical system is configured to disperse light generated by irradiating a bioparticle with light, for example, and detect the dispersed light by a number of photodetectors greater than the number of fluorescent dyes with which the bioparticles are labeled. A flow cytometer that includes such a detection optical system is called a spectral flow cytometer. In addition, the detection optical system is configured to separate light corresponding to the fluorescent wavelength range of a specific fluorescent dye from the light generated by irradiating a bioparticle with light, for example, and detect the separated light by a corresponding photodetector.

The detection unit 6102 may also include a signal processing unit that converts the electrical signal obtained by the photodetector into a digital signal. The signal processing unit may include an A/D converter as a device that performs the conversion. The digital signal obtained by the conversion by the signal processing unit may be transmitted to the information processing unit 6103. The digital signal may be treated by the information processing unit 6103 as data related to light (hereinafter also referred to as "light data"). The light data may be light data including, for example, fluorescent light data. More specifically, the light data may be light intensity data, and the light intensity may be light intensity data of light including fluorescent light (which may include feature quantities such as Area, Height, Width, etc.).

(Information Processing Section)
The information processing unit 6103 includes, for example, a processing unit that executes processing of various data (for example, optical data) and a storage unit that stores various data. When the processing unit acquires optical data corresponding to a fluorescent dye from the detection unit 6102, the processing unit may perform a fluorescence leakage correction (compensation processing) on the light intensity data. In addition, in the case of a spectral flow cytometer, the processing unit executes a fluorescence separation processing on the optical data to acquire light intensity data corresponding to the fluorescent dye. The fluorescence separation processing may be performed according to, for example, the unmixing method described in JP 2011-232259 A. When the detection unit 6102 includes an image sensor, the processing unit may acquire morphological information of the bioparticles based on an image acquired by the image sensor. The storage unit may be configured to store the acquired optical data. The storage unit may further be configured to store spectral reference data used in the unmixing processing.

When the biological sample analyzer 6100 includes a fractionation unit 6104 described below, the information processing unit 6103 can execute a judgment as to whether to fractionate biological particles based on the optical data and/or morphological information. Then, the information processing unit 6103 can control the fractionation unit 6104 based on the result of the judgment, and the fractionation unit 6104 can fractionate the biological particles.

The information processing unit 6103 may be configured to be able to output various data (e.g., optical data and images). For example, the information processing unit 6103 may output various data (e.g., two-dimensional plots, spectral plots, etc.) generated based on the optical data. The information processing unit 6103 may also be configured to be able to accept input of various data, for example, accepting gating processing on a plot by a user. The information processing unit 6103 may include an output unit (e.g., a display, etc.) or an input unit (e.g., a keyboard, etc.) for executing the output or input.

The information processing unit 6103 may be configured as a general-purpose computer, for example, as an information processing device equipped with a CPU, RAM, and ROM. The information processing unit 6103 may be included in a housing in which the light irradiation unit 6101 and the detection unit 6102 are provided, or may be located outside the housing. In addition, various processes or functions by the information processing unit 6103 may be realized by a server computer or a cloud connected via a network.

(Fraction section)
The sorting unit 6104 executes sorting of the bioparticles according to the determination result by the information processing unit 6103. The sorting method may be a method of generating droplets containing bioparticles by vibration, applying an electric charge to the droplets to be sorted, and controlling the direction of travel of the droplets by electrodes. The sorting method may be a method of controlling the direction of travel of the bioparticles in the flow path structure and sorting them. The flow path structure is provided with, for example, a control mechanism using pressure (spray or suction) or electric charge. An example of the flow path structure is a chip (for example, a chip described in JP 2020-76736 A) having a flow path structure in which a flow path C branches into a recovery flow path and a waste liquid flow path downstream thereof, and specific bioparticles are collected into the recovery flow path.

2. Second embodiment (biological sample analysis system)

The optical detection device may be used not only in a flow cytometer, but also in an analysis system other than a flow cytometer. In other words, the present disclosure also provides a biological sample analysis system including the optical detection device described in 1 above.

In one embodiment, the biological sample analysis system may include a light detection device configured to detect light generated by irradiating biological particles flowing through a flow path with light. As described in 1. above, the light detection device may include a plurality of light detector arrays in which light detector elements are arranged in a line, and the plurality of light detector arrays may be arranged at predetermined intervals along a direction intersecting the array direction of each light detector array.
The biological sample analyzing system may be configured to have a light irradiation unit, a detection unit, and an information processing unit, as described in 1 above. Furthermore, the system may have a fractionation unit. In the biological sample analyzing system, the light irradiation unit, the detection unit, and the information processing unit (and optionally the fractionation unit) may be incorporated into one device, or may be distributed among multiple devices.

In addition, the bioparticles irradiated with light do not necessarily have to flow through the flow path. That is, the bioparticles irradiated with light may be present in an area other than the flow path, for example, bioparticles present in a non-flowing sample. In addition, the object irradiated with light may be a particle other than a bioparticle, or a biomaterial other than a particle. For example, the light detection device may be used in a microscope system, a biomaterial system (e.g., a nucleic acid or protein analysis system), or a biomaterial amplification system (e.g., a nucleic acid amplification system).
That is, the present disclosure also provides a biological sample analyzing system having a light detection device configured to detect light generated by irradiating a biological sample with light.

3. Third embodiment (light detection device)

The present disclosure also provides the optical detection device described in 1 above. The optical detection device is suitable for analyzing biological particles. For example, the optical detection device may be used to detect light generated by irradiating biological particles with light.

In one embodiment, the light detection device may be used in combination with a light irradiation unit that irradiates the bioparticles with light at multiple light irradiation positions along the flow direction of the flow channel. That is, the present disclosure also provides a combination of the light irradiation unit and the light detection device. The light irradiation unit is as described in 1. above.

The light detection device may be used in combination with a spectroscopic optical system that disperses the multiple lights generated by the light irradiation at the multiple light irradiation positions. That is, the present disclosure also provides a combination of the spectroscopic optical system and the light detection device. The spectroscopic optical system is as described in 1. above.

The spectroscopic optical system may have two or more of the multiple photodetector arrays having the same detection wavelength range.

Note that the shape and number of each optical element (e.g., light-guiding optical system, spectroscopic optical system, and telecentric focusing lens, etc.) shown in the drawings attached to this specification are schematic examples, and it is clear to those skilled in the art that the configuration (shape, number, etc.) is not limited to those shown in the drawings. Those skilled in the art can appropriately design each optical element so that it exerts the desired function. For example, one lens shown in each drawing is not limited to only one lens, but may be configured as one lens system, that is, it may be a collection of two or more lenses.

The present disclosure also provides the following:
[1]
The device has a light detection device that detects light generated by irradiating light onto biological particles flowing through the flow path,
The light detection device includes a plurality of light detector arrays each having a line of light detector elements;
The plurality of photodetector arrays are arranged at predetermined intervals along a direction intersecting the array direction of each of the photodetector arrays.
Flow cytometer.
[2]
The flow cytometer according to claim 1, wherein the plurality of photodetector arrays are arranged to correspond to a flow direction of the flow channel.
[3]
Each of the plurality of photodetector arrays comprises:
a photodetector array having a row of photomultiplier tube elements; or
a photodetector array having a row of avalanche photodiode elements; or
The photodetector array is a photodetector array in which photomultiplier tube elements are arranged in a row, or a photodetector array in which avalanche photodiode elements are arranged in a row.
A flow cytometer according to [1] or [2].
[4]
Each of the plurality of photodetector arrays is a photodetector array in which photomultiplier tube elements are arranged in a row,
The photomultiplier tube element is a photomultiplier tube element including a dynode having a semiconductor element or a photomultiplier tube element including a multi-stage dynode.
A flow cytometer according to [1] or [2].
[5]
The flow cytometer according to claim 1 or 2, wherein the light detection device is a multi-pixel photon counter.
[6]
The flow cytometer has a light irradiation unit that irradiates light onto bioparticles flowing through the flow path at a plurality of light irradiation positions along a flow direction of the flow path.
The flow cytometer according to any one of [1] to [5].
[7]
The flow cytometer according to claim 6, wherein the plurality of light irradiation positions are irradiated with light having wavelengths different from one another.
[8]
A flow cytometer as described in [6] or [7], which is configured to detect light resulting from light irradiation at two or more of the multiple light irradiation positions by a single light detection device.
[9]
The flow cytometer according to any one of [1] to [8], wherein each of the multiple photodetector arrays is configured to enable gain adjustment independently of each other.
[10]
A flow cytometer described in any one of [1] to [9], wherein each of the multiple photodetector units of the photodetector array is configured to be able to adjust the gain independently of each other.
[11]
A flow cytometer described in any one of [1] to [10], wherein one or more of the multiple photodetector arrays are configured to be able to change the position of each of the photodetector arrays in a direction intersecting the array direction independently of each other.
[12]
A flow cytometer described in any one of [1] to [11], wherein one or more of the multiple photodetector arrays are configured so that the position of each of the photodetector arrays in the array direction can be changed independently of each other.
[13]
The light detection device further comprises a microlens array;
The flow cytometer according to any one of [1] to [12], wherein the microlens array is arranged so that each lens constituting the microlens array is located above each photodetector element of the photodetection device.
[14]
the flow cytometer has a propagation optical path that propagates light generated by the light irradiation to the light detection device;
the propagation path includes one or more optical fibers;
The flow cytometer according to any one of [1] to [13].
[15]
The flow cytometer comprises:
a light irradiation unit that irradiates light onto the bioparticles flowing through the flow path at a plurality of light irradiation positions along the flow direction of the flow path; and
a propagation optical path for propagating light generated by the light irradiation by the light irradiation unit to the light detection device,
the propagation path includes a plurality of optical fiber core paths;
The light incident side ends of the plurality of optical fiber core optical paths are arranged so as to correspond to the intervals between the plurality of light irradiation positions.
The flow cytometer according to any one of [1] to [13].
[16]
The flow cytometer comprises:
a light irradiation unit that irradiates light onto the bioparticles flowing through the flow path at a plurality of light irradiation positions along the flow direction of the flow path; and
a propagation optical path for propagating light generated by the light irradiation by the light irradiation unit to the light detection device,
the propagation path includes a plurality of optical fiber core paths;
The light output ends of the plurality of optical fiber core optical paths are arranged to correspond to the intervals of the photodetector array.
The flow cytometer according to any one of [1] to [14].
[17]
the flow cytometer further includes a propagation optical path that propagates light generated by irradiating light onto bioparticles flowing through the flow path to the light detection device;
The propagation light path passes through a field stop.
The flow cytometer according to any one of [1] to [13].
[18]
The flow cytometer according to any one of [1] to [17], wherein at least one of the multiple photodetector arrays has 10 or more photodetector units.
[19]
A flow cytometer according to any one of [1] to [18], wherein a plurality of photodetectors included in the photodetection device are configured to detect light independently of each other in time.
[20]
The device has a light detection device that detects light generated by irradiating light onto biological particles flowing through the flow path,
The light detection device includes a plurality of light detector arrays each having a line of light detector elements;
The plurality of photodetector arrays are arranged at predetermined intervals along a direction intersecting the array direction of each of the photodetector arrays.
Biological sample analysis system.
[21]
a photodetector array having a plurality of photodetector elements arranged in a line;
The plurality of photodetector arrays are arranged at predetermined intervals along a direction intersecting an array direction of each of the photodetector arrays, and
Used to detect light generated by irradiating biological particles flowing through a flow channel.
Light detection device.
[22]
The optical detection device according to [21], which is used in combination with a light irradiation unit that irradiates light onto the bioparticles at a plurality of light irradiation positions along the flow direction of the flow channel.
[23]
The light detection device according to [21] or [22], which is used in combination with a spectroscopic optical system that separates a plurality of light beams generated by light irradiation at the plurality of light irradiation positions.
[24]
The optical detection device according to any one of [21] to [23], wherein two or more of the plurality of optical detector arrays include at least one optical detector element having the same detection wavelength range.

200 Flow cytometer 210 Flow cell 220 Objective lens 230 Flow path side light guiding optical system 240 Field stop 250 Detector side light guiding optical system 260 Spectroscopic optical system 270 Telecentric condenser lens 280 Light detection device

Claims (24)

The device has a light detection device that detects light generated by irradiating light onto biological particles flowing through the flow path,
The light detection device includes a plurality of light detector arrays each having a line of light detector elements;
The plurality of photodetector arrays are arranged at predetermined intervals along a direction intersecting the array direction of each of the photodetector arrays.
Flow cytometer. The flow cytometer of claim 1, wherein the plurality of photodetector arrays are arranged to correspond to the flow direction of the flow channel. Each of the plurality of photodetector arrays comprises:
a photodetector array having a row of photomultiplier tube elements; or
a photodetector array having a row of avalanche photodiode elements; or
The photodetector array is a photodetector array in which photomultiplier tube elements are arranged in a row, or a photodetector array in which avalanche photodiode elements are arranged in a row.
2. The flow cytometer of claim 1. Each of the plurality of photodetector arrays is a photodetector array in which photomultiplier tube elements are arranged in a row,
The photomultiplier tube element is a photomultiplier tube element including a dynode having a semiconductor element or a photomultiplier tube element including a multi-stage dynode.
2. The flow cytometer of claim 1. The flow cytometer of claim 1, wherein the light detection device is a multi-pixel photon counter. The flow cytometer has a light irradiation unit that irradiates light onto bioparticles flowing through the flow path at a plurality of light irradiation positions along a flow direction of the flow path.
2. The flow cytometer of claim 1. The flow cytometer according to claim 6, wherein the plurality of light irradiation positions are irradiated with light having mutually different wavelengths. The flow cytometer according to claim 6, which is configured to detect light resulting from light irradiation at two or more of the multiple light irradiation positions using a single light detection device. The flow cytometer of claim 1, wherein each of the multiple photodetector arrays is configured to have gain adjustable independently of each other. The flow cytometer according to claim 1, wherein each of the multiple photodetector units in the photodetector array is configured to have gain adjustment independent of each other. The flow cytometer of claim 1, wherein one or more of the multiple photodetector arrays are configured to be able to change the position of each of the photodetector arrays in a direction intersecting the array direction independently of each other. The flow cytometer according to claim 1, wherein one or more of the multiple photodetector arrays are configured to be able to change the position of each of the photodetector arrays in the array direction independently of each other. The light detection device further comprises a microlens array;
2. The flow cytometer according to claim 1, wherein the microlens array is provided such that each lens constituting the microlens array is located above each photodetector element of the photodetection device. the flow cytometer has a propagation optical path that propagates light generated by the light irradiation to the light detection device;
the propagation path includes one or more optical fibers;
2. The flow cytometer of claim 1. The flow cytometer comprises:
a light irradiation unit that irradiates light onto the bioparticles flowing through the flow path at a plurality of light irradiation positions along the flow direction of the flow path; and
a propagation optical path for propagating light generated by the light irradiation by the light irradiation unit to the light detection device,
the optical propagation path includes a plurality of optical fiber cores;
The plurality of optical fiber cores are arranged at their light input ends so as to correspond to the intervals between the plurality of light irradiation positions.
2. The flow cytometer of claim 1. The flow cytometer comprises:
a light irradiation unit that irradiates light onto the bioparticles flowing through the flow path at a plurality of light irradiation positions along the flow direction of the flow path; and
a propagation optical path for propagating light generated by the light irradiation by the light irradiation unit to the light detection device,
the optical propagation path includes a plurality of optical fiber cores;
the plurality of optical fiber cores are arranged at their light emitting ends so as to correspond to the intervals of the photodetector array;
2. The flow cytometer of claim 1. the flow cytometer further includes a propagation optical path that propagates light generated by irradiating light onto bioparticles flowing through the flow path to the light detection device;
The propagation light path passes through a field stop.
2. The flow cytometer of claim 1. The flow cytometer of claim 1, wherein at least one of the plurality of photodetector arrays has 10 or more photodetector elements. The flow cytometer according to claim 1, wherein the multiple photodetector elements included in the light detection device are configured to detect light independently of each other in time. The device has a light detection device that detects light generated by irradiating light onto biological particles flowing through the flow path,
The light detection device includes a plurality of light detector arrays each having a line of light detector elements;
The plurality of photodetector arrays are arranged at predetermined intervals along a direction intersecting the array direction of each of the photodetector arrays.
Biological sample analysis system. a photodetector array having a plurality of photodetector elements arranged in a line;
The plurality of photodetector arrays are arranged at predetermined intervals along a direction intersecting an array direction of each of the photodetector arrays, and
Used to detect light generated by irradiating biological particles flowing through a flow channel.
Light detection device. The optical detection device according to claim 21, which is used in combination with a light irradiation unit that irradiates the bioparticles with light at multiple light irradiation positions along the flow direction of the flow channel. The optical detection device according to claim 21, which is used in combination with a spectroscopic optical system that separates the multiple lights generated by the light irradiation at the multiple light irradiation positions. 22. The optical detection apparatus of claim 21, wherein two or more of the plurality of optical detector arrays include at least one optical detector element having the same detection wavelength range.