JP5078929B2 - Cell sorter and sample separation method - Google Patents

Description

  The present invention relates to a cell sorter and a sample sorting method, and more particularly to a cell sorter and a method for selectively sorting a target sample from a large number of measurement samples such as cells.

  In the medical field, separating specific cells from a solution containing a plurality of types of cells is a very important process for enhancing the medical effect. In recent years, as a means for such separation, by forming a flow of a solution in which a large number of samples such as cells are dispersed, each sample is irradiated with laser light to analyze fluorescence, scattered light, etc. emitted from the sample. Flow cytometers that identify sample types and sort target samples are now used. Since this flow cytometer enables analysis of a large number of samples in a short time, it is attracting attention especially for use in the selective collection of stem cells in the field of regenerative medicine.

  Stem cells are cells that maintain the ability to replicate the same cells again after cell division and have the ability to differentiate into other types of cells, and this ability constitutes tissues and organs Can produce cells. Stem cells exist in many tissues, but the number thereof is small, and usually only a very small amount can be found from a large amount of collected cell samples. For this reason, it is required to select and collect stem cells with high accuracy.

  As a method for separating a target sample from a large number of samples, for example, in Patent Document 1, droplets are sequentially formed and dropped from a flow of a solution in which a large number of samples are dispersed, and a droplet including a target sample is used. A method is disclosed in which each droplet is allowed to pass through a predetermined electric field in the middle of falling after being selectively charged. When passing through the electric field, only the charged droplet receives an electrostatic force from the electric field and bends its falling direction, so that the target sample contained in the droplet can be separated from other samples.

JP-A-62-255868

  However, if the droplet containing the target sample is charged in order to sort the target sample, the target sample made of cells or the like may be significantly damaged by the applied charge. In particular, when a stem cell is used as a target sample, there is a risk that it may be unable to differentiate normally due to damage or a defective cell such as a cancer cell may be expressed.

  The present invention has been made to solve such a conventional problem, and an object thereof is to provide a cell sorter and a sample sorting method capable of selectively sorting a target sample without giving a large damage. To do.

In the cell sorter according to the present invention, each measurement obtained by passing a large number of measurement samples including a target sample and other samples dispersed in a solution and flowing in a row at intervals through an irradiation area of a light beam. A cell sorter that selectively separates a target sample based on optical information of the sample, a droplet forming unit that sequentially forms droplets from a solution in which a measurement sample is dispersed, and a droplet forming unit that drops the droplets A liquid ejecting means for ejecting liquid from the side toward the liquid droplet and a liquid ejecting means that is selectively driven based on the optical information of the measurement sample to the liquid droplet that is in the middle of falling, including the target sample , has been a liquid ejected from the liquid ejecting means at a position off-center portion of the droplets collide to deflect the falling trajectory of the droplets, minute droplets containing a target sample from other droplets It is obtained and a control unit for.

Here, the control unit deflects the drop trajectory of the droplet by causing the liquid ejected from the liquid ejecting means to collide with the droplet in the middle of the fall including the target sample at a position shifted from the central portion of the droplet. Can do. The liquid ejecting means ejects a plurality of small-diameter liquids, and the control unit ejects a plurality of liquid droplets ejected from the liquid ejecting means at positions shifted from the central portion of the liquid droplets in the middle of dropping including the target sample. Alternatively, the drop trajectory of the droplet may be deflected by colliding with a small diameter liquid. The liquid ejecting means ejects a ring-shaped liquid, and the control unit ejects a ring-shaped liquid that is ejected from the liquid ejecting means so as to surround the central portion of the liquid droplet in the middle of the fall including the target sample. The drop trajectory of the droplet may be deflected by colliding with the liquid.
Preferably, the liquid ejecting unit ejects the liquid by driving the piezoelectric element.
In addition, the liquid ejecting means includes a plurality of liquid ejecting units that eject liquid from different directions toward the droplets falling by the droplet forming unit, and the control unit is configured to By selectively driving one of the liquid ejecting units, the drop trajectory of the droplet can be configured to be deflected in a direction corresponding to the driven liquid ejecting unit.
The liquid cell further includes a flow cell that circulates the solution in which the measurement sample is dispersed and discharges the solution from the opening end, and the droplet forming unit vibrates the opening end of the flow cell, thereby causing the droplet to pass from the solution passing through the opening end. You may make it have the vibrator | oscillator formed.

The sample separation method according to the present invention is obtained by passing a large number of measurement samples including a target sample and other samples, which are dispersed in a solution and flow in a row at intervals, through an irradiation region of a light beam. In this method, the target sample is selectively sorted based on the optical information of the measurement sample, and droplets are sequentially formed and dropped from the solution in which the measurement sample is dispersed. against the drop of a liquid middle drop containing, other droplets containing the target sample by deflecting the falling trajectory of the droplets by colliding the liquid ejected from the side in a position off-center portion of the droplet It is a method of separating from the droplets.

  In addition, by selectively ejecting liquid from different directions to the drop in the middle of the fall including the target sample based on the optical information of the measurement sample, the drop trajectory of the drop is changed to one of a plurality of directions. You may make it deflect.

  According to the present invention, since the liquid jetted from the side collides with the droplet in the middle of the fall including the target sample, thereby deflecting the drop trajectory of the droplet, the target sample can be selected without damaging it. It is possible to sort them automatically.

It is a figure which shows the structure of the flow cytometer provided with the cell sorter which concerns on Embodiment 1 of this invention. 3 is a cross-sectional view showing a configuration of a liquid ejecting unit used in Embodiment 1. FIG. It is sectional drawing which shows the principal part of the liquid injection part of FIG. 2 at the time of liquid injection. 6 is a partial cross-sectional view showing a configuration of a main part of a cell sorter according to Embodiment 2. FIG. 6 is a diagram illustrating a schematic configuration of a cell sorter according to Embodiment 3. FIG. FIG. 10 is a diagram illustrating a state in which liquid is ejected to droplets including a target sample in the cell sorter according to the fourth embodiment. FIG. 10 is a diagram showing a state in which liquid is ejected to droplets including a target sample in a cell sorter according to a modification of the fourth embodiment. FIG. 10 is a diagram showing a state in which liquid is ejected to droplets including a target sample in a cell sorter according to another modification of the fourth embodiment.

Hereinafter, the present invention will be described in detail based on a preferred embodiment shown in the drawings.
Embodiment 1
FIG. 1 shows the configuration of a flow cytometer equipped with a cell sorter according to Embodiment 1 of the present invention. The flow cytometer has a cylindrical flow cell 10 arranged in a substantially vertical direction. The flow cell 10 is for circulating the solution in which the measurement sample S is dispersed, and an open end 12 is formed at the lower end of the flow cell 10. In the flow cell 10, by discharging the sample liquid including the measurement sample S in the flow of the sheath liquid, a very thin sample liquid flow is formed due to the hydrodynamic narrowing effect, and the measurement sample S is arranged in one row. Thus, it is configured to flow to the opening end 12 at a predetermined speed V with an appropriate interval.

  An optical unit 14 is arranged so as to surround the outer periphery of the flow cell 10. The optical unit 14 includes a light source unit 16 for forming a laser beam irradiation region R1 having a predetermined wavelength in the flow cell 10 and a light receiving unit 18 for detecting forward scattered light generated from the measurement sample S irradiated with the laser beam. And a light receiving unit 20 for detecting side scattered light and fluorescence generated from the measurement sample S irradiated with the laser light. One light receiving unit 18 is disposed at a position facing the light source unit 16 with the flow cell 10 interposed therebetween, and the other light receiving unit 20 is disposed in a direction perpendicular to the irradiation direction of the laser light from the light source unit 16. . For example, a photodiode or a phototransistor can be used as the light receiving unit 18 that detects forward scattered light, and a photomultiplier tube (PMT) is used as the light receiving unit 20 that detects side scattered light and fluorescence. Can be used.

  An analysis unit 22 is connected to the light receiving units 18 and 20. The analysis unit 22 calculates light information such as the intensity of forward scattered light, the intensity of side scattered light, the intensity of fluorescence, and the fluorescence lifetime based on the detection signals obtained by the light receiving units 18 and 20.

  A vibrator 24 is attached to the flow cell 10 in the vicinity of the open end 12. The vibrator 24 is for sequentially forming droplets D from the solution flowing down through the open end 12 by applying vibration to the internal solution via the flow cell 10. A number of droplets corresponding to the frequency of vibration applied by the vibrator 24 are formed per unit time. As the vibrator 24, for example, a piezoelectric element is used.

Further, the liquid ejecting unit 26 is disposed so as to face the predetermined position R2 directly below the flow cell 10 from the side. The liquid ejecting portion 26 is for ejecting the liquid L from the side with the predetermined position R2 directed toward the falling droplet D. The liquid droplet D that has not been ejected with the liquid L falls vertically downward, but the liquid droplet D that has collided with the liquid L ejected from the liquid ejecting unit 26 deflects the dropping trajectory from the predetermined position R2, and the liquid ejection A parabola is drawn and it falls, moving to the opposite side to the arrangement place of the part 26.
The liquid L ejected from the liquid ejecting unit 26 is not particularly limited as long as it does not affect the characteristics of the measurement sample S. For example, the same as the sheath liquid and the sample liquid circulated in the flow cell 10. Liquid can be used.

A control unit 28 for controlling the driving of the liquid ejecting unit 26 is connected to the analyzing unit 22 and the liquid ejecting unit 26. The control unit 28 stores optical information specific to the target sample previously input by the operator. The control unit 28 compares the optical information calculated by the analysis unit 22 with optical information specific to the target sample stored in advance, so that the measurement sample S that has passed through the laser light irradiation region R1 in the flow cell 10 is the target. It is determined whether or not it is a sample, and when the droplet D including the measurement sample S determined to be the target sample passes the predetermined position R2, the liquid ejecting unit 26 is driven, and the liquid L is applied to the droplet D. Collide.
The control unit 28 is also connected to the light source unit 16 and the vibrator 24 of the optical unit 14.

Furthermore, a waste liquid container 30 for storing the droplets D that have not been ejected with the liquid L is disposed directly below the flow cell 10 below the liquid ejection unit 26, and on the side of the waste liquid container 30, A collection container 32 for storing the droplet D that has collided with the liquid L and deflected the drop trajectory is disposed.
The vibrator 24, the liquid ejecting unit 26, the control unit 28, the waste liquid container 30, and the recovery container 32 constitute the cell sorter according to the first embodiment.

  FIG. 2 shows the configuration of the liquid ejecting unit 26. The liquid ejecting unit 26 is a so-called ink jet type ejecting unit that uses the expansion and contraction operation of the piezoelectric element. A pressure chamber 44 and a liquid channel 46 and a nozzle 48 communicating with the pressure chamber 44 are formed in the head portion 42 supported by the bracket 40. An actuator 52 made of a piezoelectric element is disposed on the back of the pressure chamber 44 via a vibration film 50, and the surface of the head portion 42 on which the nozzle 48 is formed is coated with a water repellent film 54.

The head portion 42 is formed of, for example, a composite material made of epoxy resin. In particular, the vibration film 50 formed of a part of the head portion 42 and interposed between the pressure chamber 44 and the actuator 52 has a predetermined elasticity and flexibility. It has flexibility. In addition, an electrode (not shown) for applying a voltage from the outside is formed on the actuator 52, and the piezoelectric element constituting the actuator 52 extends in the direction of the pressure chamber 44 when a voltage is applied. Polarized.
For this reason, when a pulsed voltage is applied to the actuator 52 in a state where the liquid L is supplied to the pressure chamber 44 via the liquid flow path 46, the vibration film 50 is pressed and deformed as shown in FIG. The actuator 52 extends in the direction of the pressure chamber 44, whereby the pressure in the pressure chamber 44 rises and the liquid L is ejected from the nozzle 48.

Next, the operation of the flow cytometer shown in FIG. 1 will be described.
First, the light source unit 16 and the vibrator 24 of the optical unit 14 are driven by the control unit 28 to form an irradiation region R1 of laser light having a predetermined wavelength in the flow cell 10 and in the vicinity of the open end 12 of the flow cell 10. Vibration is applied to the. In this state, the sheath liquid is supplied into the flow cell 10 and the sample liquid including the measurement sample S is discharged into the flow of the sheath liquid, whereby the measurement sample S is arranged in a row and is predetermined while being appropriately spaced. To the open end 12 at a velocity V of
In the control unit 28, based on the predetermined speed V of the measurement sample S and the distance between the laser light irradiation region R1 and the predetermined position R2, the measurement sample S passes through the laser light irradiation region R1 and then the predetermined position R2. It is assumed that the required time T to reach is calculated and stored.

  When the measurement sample S flowing in the flow cell 10 enters the laser beam irradiation region R1 and is irradiated with laser light having a predetermined wavelength, the fluorescent dye contained in the measurement sample S is excited to generate fluorescence and the measurement sample S. Forward scattered light and side scattered light are generated. Forward scattered light generated from the measurement sample S is detected by the light receiving unit 18, and a detection signal is transmitted from the light receiving unit 18 to the analyzing unit 22. On the other hand, fluorescence and side scattered light generated from the measurement sample S are detected by the light receiving unit 20, and a detection signal is transmitted from the light receiving unit 20 to the analysis unit 22. Based on these detection signals, the analysis unit 22 calculates light information such as the intensity of forward scattered light, the intensity of side scattered light, the intensity of fluorescence, and the fluorescence lifetime, and outputs the light information to the control unit 28.

  The control unit 28 compares the light information specific to the target sample previously input and stored by the operator with the light information calculated by the analysis unit 22. In addition, as light information compared here, any one of the information regarding the intensity | strength of the forward scattered light mentioned above, the intensity | strength of side scattered light, the intensity | strength of fluorescence, and the fluorescence lifetime may be used, or multiple The information may be compared with each other.

  When the optical information calculated by the analysis unit 22 matches the optical information stored in the control unit 28, the control unit 28 sets the measurement sample S that has passed through the laser light irradiation area R1 in the flow cell 10 as the target. Judge as a sample. On the other hand, when the optical information calculated by the analysis unit 22 does not match the optical information stored in the control unit 28, the control unit 28 determines that the measurement sample S that has passed through the laser light irradiation area R <b> 1 in the flow cell 10. Judge that it is not the target sample.

  The measurement sample S that has passed through the laser light irradiation region R1 flows downward through the flow cell 10 at a predetermined speed V together with the solution composed of the sample liquid and the sheath liquid, and flows out from the open end 12. Since vibration is applied to the internal solution via 10, droplets D are sequentially formed from the solution flowing down through the open end 12 and fall. As a result, the falling droplets D sequentially pass through the predetermined position R2 that the liquid ejecting unit 26 faces.

  Therefore, the control unit 28 drives the liquid ejecting unit 26 at a timing when the droplet D including the measurement sample S determined to be the target sample based on the optical information input from the analysis unit 22 reaches the predetermined position R2. Specifically, when the required time T that has been calculated and stored in advance after the measurement sample S has passed through the laser light irradiation region R1, the control unit 28 controls the actuator 52 of the liquid ejecting unit 26. A pulsed voltage is applied, whereby the actuator 52 extends to compress the pressure chamber 44, and the liquid L is ejected from the nozzle 48.

  In this way, the droplet D including the target sample collides with the liquid L ejected from the liquid ejecting unit 26 at the predetermined position R2 in the middle of dropping, and deflects the dropping trajectory. That is, the droplet D that has fallen vertically downward from the open end 12 of the flow cell 10 to the predetermined position R2 has a velocity component that is directed laterally from the predetermined position R2 due to the collision of the liquid L, and is a parabola. Fall while drawing. As a result, the droplet D containing the target sample is accommodated in the collection container 32 arranged at a position shifted laterally from directly below the flow cell 10.

  On the other hand, the control unit 28 applies the liquid ejecting unit 26 to the droplet D including the measurement sample S that is determined not to be the target sample based on the optical information input from the analyzing unit 22 even when the droplet D reaches the predetermined position R2. The liquid L is not jetted. That is, the droplet D containing the measurement sample S other than the target sample falls down vertically as it passes through the predetermined position R <b> 2 and is accommodated in the waste liquid container 30 disposed immediately below the flow cell 10.

As described above, by selectively ejecting the liquid L from the liquid ejecting unit 26 onto the droplet D, only the droplet D including the target sample is accommodated in the recovery container 32 and the droplet D not including the target sample. Can be stored in the waste liquid container 30. Since the droplets D are sorted only by jetting the liquid L without applying the charge as used in the prior art, it is possible to sort the target sample made up of cells and the like without causing any significant damage. Become.
Further, since the ink jet type liquid ejecting section 26 is used, tens of thousands of liquids L can be ejected per second, and a large number of measurement samples S can be separated in a short time.

Embodiment 2
FIG. 4 shows the configuration of the main part of the cell sorter according to the second embodiment. In the cell sorter according to the first embodiment shown in FIG. 1, the space between the flow cell 10 and the waste liquid container 30 and the recovery container 32 is open, but the waste liquid container 30 and the recovery container 32 are opened from the open end 12 of the flow cell 10. The drop trajectory of the droplet D reaching up to can be covered with a tubular member. In this case, at a predetermined position R2 where the liquid L is selectively ejected onto the droplet D, as shown in FIG. 4, a nozzle hole 62 is formed in the wall portion of the tubular member 60, and the liquid ejecting portion is formed outside the nozzle hole 62. 26, and the tubular member 60 may be branched into a vertical pipe portion 64 toward the waste liquid container 30 and a branch pipe portion 66 toward the recovery container 32.
Since the droplet D falls through the tubular member 60, the selective collision of the liquid L to the droplet D is ensured without being affected by the surrounding atmosphere such as an air flow, and the reliability of the target sample separation Will improve.

Embodiment 3
FIG. 5 shows a schematic configuration of the cell sorter according to the third embodiment. This cell sorter is the same as the cell sorter of the first embodiment shown in FIG. 1, in addition to the liquid ejecting portion 26 arranged corresponding to the predetermined position R2, and corresponding to another predetermined position R3 below the predetermined position R2. One liquid ejecting unit 70 is arranged, a control unit 72 is connected to the liquid ejecting units 26 and 70 instead of the control unit 28, and another collecting container 74 is arranged in addition to the collecting container 32. The control unit 72 is also connected to the light source unit 16, the analysis unit 22, and the vibrator 24 of the optical unit 14 described in the first embodiment.

  The liquid ejecting unit 70 has the same configuration as the liquid ejecting unit 26 described in the first embodiment, and ejects the liquid L from the side with the predetermined position R3 toward the falling droplet D. It arrange | positions so that the liquid L may be ejected from the direction different from the part 26. FIG. The collection container 74 is disposed on the lower side opposite to the liquid ejecting unit 70 with the predetermined position R3 interposed therebetween. The droplets D that are not subjected to the ejection of the liquid L from the liquid ejecting unit 70 fall vertically downward at the predetermined position R3, but the droplets D that the liquid L ejected from the liquid ejecting unit 70 collide are predetermined. The fall trajectory is deflected from the position R3 and falls to the collection container 74 while drawing a parabola while moving to the side opposite to the place where the liquid ejecting unit 70 is arranged.

  The control unit 72 stores optical information specific to the first target sample and optical information specific to the second target sample, which have been input by the operator in advance, and the control unit 72 is the analysis unit 22. By comparing the calculated light information with the previously stored light information, whether the measurement sample S that has passed through the laser light irradiation area R1 in the flow cell 10 is the first target sample or the second target sample, or Determine if it is another target sample.

  Then, when determining that the sample is the first target sample, the control unit 72 drives the liquid ejecting unit 26 at a timing when the droplet D including the measurement sample S passes the predetermined position R2, and the droplet D is changed to the droplet D. The liquid L is made to collide, the fall trajectory is deflected, and the droplet D is stored in the collection container 32. On the other hand, when determining that the measurement sample S that has passed through the laser light irradiation area R1 is the second target sample, the control unit 72 performs liquid ejection at the timing when the droplet D including the measurement sample S passes through the predetermined position R3. The unit 70 is driven to cause the liquid L to collide with the droplet D, deflect the fall trajectory, and store the droplet D in the collection container 74. If it is determined that the sample is neither the first target sample nor the second target sample, neither the liquid ejecting units 26 and 70 are driven, and the droplet D passes through the predetermined positions R2 and R3. It falls down vertically as it is and is stored in the waste liquid container 30.

In this way, the first and second target samples can be separated and accommodated in the collection containers 32 and 74, respectively. If the two liquid ejecting units 26 and 70 can be arranged in different directions corresponding to one predetermined position, the arrangement heights of the liquid ejecting units 26 and 70 are not different from each other. The liquid ejecting units 26 and 70 may be arranged in parallel corresponding to the common predetermined position R2.
Also for the cell sorter of the third embodiment, the tubular member shown in the second embodiment can cover the drop trajectory of the droplet D.
Similarly, three or more types of target samples can be separated by arranging three or more sets of liquid ejecting units and collection containers.

Embodiment 4
The ejection of the liquid L onto the droplet D including the measurement sample S can be performed so that the liquid L collides with the central portion of the droplet D. However, as shown in FIG. You may make it collide with the position which shifted | deviated from the center part. In this way, it is possible to perform the separation while avoiding that the measurement sample S positioned at the center portion of the droplet D is directly subjected to the impact caused by the collision of the liquid L. This is particularly effective when the measurement sample S that is vulnerable to damage is separated.
Further, as shown in FIG. 7, a plurality of small-diameter liquids L1 can be dispersed and collided at positions shifted from the central portion of the droplets D. As shown in FIG. Can be made to collide with the position excluding the central portion of the droplet D. Even in this case, it is possible to perform the separation while further reducing the damage received by the measurement sample S.

  In the first to fourth embodiments described above, an ink jet type ejecting unit that uses the expansion and contraction operation of the piezoelectric element is used as the liquid ejecting unit. However, the present invention is not limited to this. For example, a solenoid coil is used and electromagnetic force is used. Then, the liquid L can be ejected by pressing the pressure chamber.

  DESCRIPTION OF SYMBOLS 10 Flow cell, 12 Open end part, 14 Optical unit, 16 Light source part, 18, 20 Light-receiving part, 22 Analysis part, 24 Vibrator, 26, 70 Liquid injection part, 28, 72 Control part, 30 Waste liquid container, 32, 74 Recovery container, 40 Bracket, 42 Head part, 44 Pressure chamber, 46 Liquid flow path, 48 Nozzle, 50 Vibration film, 52 Actuator, 54 Water repellent film, 60 Tubular member, 62 Nozzle hole, 64 Vertical pipe part, 66 Branch pipe Part, S measurement sample, D droplet, L, L1, L2 liquid, R1 laser light irradiation area, R2, R3 predetermined positions.

Claims (9)

Based on optical information of each measurement sample obtained by passing a large number of measurement samples including a target sample and other samples that are dispersed in the solution and flow in a row at intervals through the irradiation region of the light beam. A cell sorter for selectively separating the target samples,
A droplet forming section for sequentially forming and dropping droplets from a solution in which the measurement sample is dispersed;
A liquid ejecting means for ejecting a liquid from the side toward a droplet falling by the droplet forming section;
By selectively driving the liquid ejecting means based on the optical information of the measurement sample, the liquid ejecting means is moved from the liquid ejecting means to a position where the central portion of the liquid droplet is removed with respect to the dropping liquid including the target sample. A cell sorter comprising: a control unit that causes the ejected liquid to collide to deflect a drop trajectory of the droplet and to separate the droplet including the target sample from other droplets.   The control unit causes a liquid droplet ejected from the liquid ejecting means to collide with a liquid droplet that is falling while including the target sample, and deflects the liquid droplet dropping trajectory at a position shifted from a central portion of the liquid droplet. Item 2. A cell sorter according to Item 1.   The liquid ejecting means ejects a plurality of small diameter liquids,
  The control unit collides a plurality of small-diameter liquids ejected from the liquid ejecting means with respect to a droplet that is in the middle of falling, including the target sample, at a position shifted from the central portion of the droplet, thereby dropping the droplet The cell sorter according to claim 1, wherein the cell sorter is deflected.   The liquid ejecting means ejects a ring-shaped liquid,
  The control unit deflects a drop trajectory of a droplet by causing a ring-shaped liquid ejected from the liquid ejecting means to collide with a droplet in the middle of a drop including the target sample so as to surround a central portion of the droplet. The cell sorter according to claim 1. The cell sorter according to any one of claims 1 to 4, wherein the liquid ejecting means ejects liquid by driving a piezoelectric element. The liquid ejecting means has a plurality of liquid ejecting units that eject liquid from different directions toward the droplets falling by the droplet forming unit,
The control unit selectively drives one of the plurality of liquid ejecting units based on the optical information of the measurement sample, thereby corresponding to the droplet ejection trajectory to the driven liquid ejecting unit. The cell sorter according to any one of claims 1 to 5, wherein the cell sorter is deflected in an inclined direction. A flow cell that circulates the solution in which the measurement sample is dispersed and discharges the solution from the open end;
The cell sorter according to any one of claims 1 to 6 , wherein the droplet forming unit includes a vibrator that forms a droplet from a solution passing through the opening end by vibrating the opening end of the flow cell. . Based on optical information of each measurement sample obtained by passing a large number of measurement samples including a target sample and other samples that are dispersed in the solution and flow in a row at intervals through the irradiation region of the light beam. A method of selectively separating the target samples,
Drops are formed by sequentially forming droplets from the solution in which the measurement sample is dispersed,
Against the drop of a liquid middle drop containing the target sample on the basis of the optical information of the measurement sample, in a position off-center portion of the droplets by colliding the liquid ejected from the side of the falling trajectory of the droplet A sample separation method comprising: separating a droplet including the target sample from another droplet by deflecting the sample. Based on the optical information of the measurement sample, by selectively ejecting liquid from different directions to the falling droplet including the target sample, the dropping trajectory of the droplet is set to any one of a plurality of directions. The sample sorting method according to claim 8 , wherein the sample is deflected.

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