Detailed Description
Embodiments of the present application are further described below with reference to the accompanying drawings. The same or similar reference numbers in the drawings refer to the same or similar elements or elements having the same or similar functions throughout.
In addition, the embodiments of the present application described below with reference to the drawings are exemplary only for explaining the embodiments of the present application and are not to be construed as limiting the present application.
In the present application, "first," "second," "third," "fourth," and "fifth" are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance, order, or number of technical features indicated. Thus, features defining "first," "second," etc. may explicitly or implicitly include one or more of the described features. In the description of the present application, unless otherwise defined, the meaning of "a plurality" is two or more.
In the present application, "mounted" and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected, unless otherwise specifically defined and limited; can be mechanically connected, electrically connected or can be communicated with each other; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.
In the present application, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.
In the present application, the terms "nucleic acid sequencing," "sequencing," and "sequencing" are equivalent, including DNA sequencing and/or RNA sequencing, including long fragment sequencing and/or short fragment sequencing; the so-called "sequencing reaction" is the same sequencing reaction. Typically, in nucleic acid sequencing, a single base/nucleotide on a template nucleic acid can be identified/determined by a single sequencing reaction, the base being selected from at least one of A, T, C, G and U. In sequencing-by-synthesis (SBS) and/or sequencing-by-ligation (SBL), a round of sequencing reactions includes extension reactions (base extension), signal detection (e.g., photo/image acquisition) and radical excision (excision of a detectable group and/or blocking group). The so-called "nucleotide analogs", i.e., substrates, also known as reversible terminators (reversible terminator), are analogs of A, T, C, G and/or U nucleotides that are capable of following the base-complementary principle to base pairing with a particular type while being capable of blocking or inhibiting the binding of a nucleotide/substrate to the next nucleotide position of a template strand. One round of sequencing reactions includes one or several repeated reactions consisting of extension reactions (base extension), signal detection and radical excision; for example, four nucleotide analogs bearing the same detectable label, e.g., bearing the same fluorescent molecule, and a round of sequencing reactions includes four repeated reactions of the four corresponding nucleotides that occur sequentially; for another example, four nucleotide analogs with two detectable labels separated by two detectable labels, the detectable labels carried by each pair being identical, a round of sequencing reaction may include two repeated reactions, i.e., two nucleotides with different detectable labels are subjected to extension, signal detection, and radical cleavage in the same reaction system, the two repeated reactions effecting base type recognition at one position of the template for a round of sequencing reaction; for another example, four nucleotide analogs each carry four detectable labels with a signal detectable region, or three of the four nucleotide analogs each carry three detectable labels with a signal detectable region, another nucleotide analog does not carry a detectable label, and a round of sequencing reactions includes one repeat of the four nucleotide analogs in the same reaction system.
Referring to fig. 1-2, an embodiment of the present application provides a flow path selection valve 10, where the flow path selection valve 10 may be applied to a liquid path system 12, or the liquid path system 12 includes the flow path selection valve 10, to achieve merging, splitting, flow path switching, and/or flow control.
Referring to fig. 1 and 3, a flow path selector valve 10 of an embodiment of the present application is configured to switch between a first valve position and a second valve position, the flow path selector valve 10 having a common port 16, a plurality of first ports 18, a plurality of second ports 20, and a plurality of communication grooves 21. The communication groove 21 selectively communicates the common port 16 and the first port 18 or the first port 18 and the second port 20.
With the flow path selection valve 10 in the first valve position, the first port 18 and the second port 20 communicate through the communication groove 21. With the flow path selection valve 10 in the second valve position, the first port 18 communicates with the common port 16 through the communication groove 21.
In the flow path selection valve 10 and the liquid path system 12 according to the embodiment of the present application, each of the first ports 18 communicates with the corresponding second port 20 through the corresponding communication groove 21 in the case where the flow path selection valve 10 is in the first valve position, and each of the first ports 18 communicates with the common port 16 through the corresponding communication groove 21 in the case where the flow path selection valve 10 is in the second valve position, so that the flow path selection valve 10 has two or more passages; the flow path selection valve 10 is suitable for use in any fluid path system requiring the use of a three-way valve, particularly a plurality of three-way valves, such as those involving the need to change the direction of one or more flow paths and/or the dispensing of multiple liquids/solutions. By applying the flow path selection valve to the liquid path system 12 comprising a plurality of liquid paths/flow paths, independent or parallel three-way control of the liquid paths can be realized, and the simultaneous arrangement of a plurality of three-way valves in the liquid path system 12 can be avoided, so that the cost of the liquid path system 12 is reduced, the volume is reduced, the consumption of reagents is reduced, the reliability is improved, and the maintenance and the control are convenient.
Specifically, the number of common ports 16 is one, and the common ports 16 may serve as liquid inlets or outlets of the flow path selection valve 10. Alternatively, liquid may enter or exit the flow path selection valve 10 from the common port 16, thereby effecting split or co-current flow. Here, the common port 16 serves as a liquid inlet of the flow path selection valve 10, and liquid may enter the flow path selection valve 10 from the common port 16. The shape of the common port 16 may be a regular shape such as a circle or a polygon, or may be an irregular shape. In embodiments of the present application, the common port 16 is circular in shape for ease of forming, manufacturing, and/or connection to common tubing.
The plurality of second ports 20 are in one-to-one correspondence with the plurality of first ports 18. The plurality of communication grooves 21 are in one-to-one correspondence with the plurality of first ports 18. The number of first ports 18 may be 2, 3, 4, 5, 6, 7, 8 or more. In the embodiment shown in fig. 1, the number of first ports 18 is 8 to accommodate elements or devices comprising 8 outlets or inlets upstream or downstream of the flow path selection valve 10.
As shown in fig. 2, liquid may enter the flow path selection valve 10 from the common port 16, flow out from the 8 first ports 18, and further enter a flow cell (flow cell) 62 containing 8 channels or 8 reaction regions, so that parallel control of the liquid feed to the 8 channels or 8 reaction regions of the flow cell 62 can be achieved. The shape of the first port 18 may be a regular shape such as a circle or a polygon, or may be an irregular shape. In an embodiment of the present application, the first port 18 is circular. The first port 18 may be used as a liquid outlet or an inlet of the flow path selection valve 10.
Similarly, the present application is not limited to the number of second ports 20, and the number of second ports 20 may be 2, 3, 4, 5, 6, 7, 8, or more. In the embodiment shown in fig. 3, the number of second ports 20 is 8 to accommodate an element or device comprising 8 outlets or inlets upstream or downstream of the flow path selection valve 10, such as the flow cell 62 comprising 8 channels or 8 reaction zones downstream of the flow path selection valve 10 in fig. 2, to achieve parallel control of the 8 channels or 8 reaction zone inlets of the flow cell 62. The number of second ports 20 is equal to the number of first ports 18. The shape of the second port 20 may be a regular shape such as a circle or a polygon, or may be an irregular shape. In an embodiment of the present application, the second port 20 is circular. The second port 20 may serve as a liquid inlet or an outlet of the flow path selection valve 10. For ease of manufacture, the second port 20 may be the same size as the first port 18.
The number of communication grooves 21 is the same as the number of first ports 18 and/or second ports 20. In the embodiment of the present application, the number of the communication grooves 21 is 8. The shape of the communication groove 21 is not limited as long as it enables the communication between the first port 18 and the second port 20 when the flow path selection valve 10 is in the first valve position, and may be, for example, arc-shaped or rectangular-shaped.
In summary, in the first valve position, each first port 18 communicates with a corresponding one of the second ports 20, at which time liquid enters the flow path selection valve 10 from the second port 20 and exits from the corresponding first port 18. That is, the flow path selector valve 10 also has the function of feeding liquid simultaneously through multiple passages and discharging liquid simultaneously through multiple passages.
In the second valve position, the common port 16 communicates with each of the first ports 18 through a corresponding one of the communication grooves 21, and at this time, the liquid can enter the flow path selection valve 10 from the common port 16, pass through the communication groove 21, and then flow out of the first ports 18. In other words, in the second valve position, liquid enters the flow path selection valve 10 from one common port 16 and exits from a plurality of first ports 18. That is, the flow path selector valve 10 has a function of one-way liquid inlet and multi-way liquid outlet.
In the present embodiment, when the flow path selection valve 10 is in the first valve position, both the first port 18 and the second port 20 are blocked from the common port 16; with the flow path selection valve 10 in the second valve position, both the common port 16 and the first port 18 are blocked from the second port 20 to form separate first or second flow passages. The first flow channels and the second flow channels are multiple, so that parallel control of the inlet and the outlet of multiple reaction areas is facilitated, and independent control of the inlet and the outlet of different reaction processes on the reaction areas is also facilitated.
In some embodiments, the flow path selection valve 10 may be in a third valve position, in which case the common port 16, the plurality of first ports 18, and the plurality of second ports 20 are isolated from one another. In this way, the flow path selection valve 10 can also realize a function of controlling the blocking of the liquid in the case where the flow path selection valve 10 is in the third valve position.
In this embodiment, the flow path selection valve 10 has three modes, that is, a mode in which the first port 18 and the second port 20 communicate when the flow path selection valve 10 is in the first valve position; a mode in which the common port 16 and the first port 18 communicate when the flow path selection valve 10 is in the second valve position; in the third valve position, the common port 16, the first port 18, and the second port 20 are isolated from each other.
It should be noted that "blocking" of a plurality of ports as referred to herein means that there is no communication between the ports, or that fluid cannot enter from one or more of the ports as specified, and fluid cannot exit from another one or more of the ports as specified.
Referring to fig. 1 and 3, in certain embodiments, the flow path selection valve 10 includes a manifold 24 and a first spool 26. Referring to fig. 4-6, the manifold 24 has a common port 16, a plurality of first ports 18, and a plurality of second ports 20. Referring to fig. 7, the first spool 26 is provided with a communication groove 21. The first spool 26 may be rotated or slid relative to the manifold 24 to switch the flow path selection valve 10 between the first valve position and the second valve position.
As such, during rotation or sliding of the first spool 26, the communication groove 21 may communicate the common port 16 and the first port 18, or may communicate the first port 18 and the second port 20, such that liquid may enter the flow path selection valve 10 from the manifold 24 and exit the flow path selection valve 10 from the manifold 24.
Specifically, the manifold 24 is a flow dividing or converging module, and the manifold 24 may divide the liquid entering from the common port 16 and then flow out of the plurality of first ports 18, or may direct the liquid entering from the second port 20 and then flow out of the corresponding first ports 18. It will be appreciated that the interior of the manifold 24 has flow passages communicating with the various ports.
In the present example, the first valve spool 26 is square, and the first valve spool 26 is slidable relative to the manifold 24. The communication groove 21 is linear, and the communication groove 21 may have a bent shape, a curved shape, or the like, and the specific shape of the communication groove 21 is not limited here.
Illustratively, the number of communication slots 21 is the same as the number of first ports 18, and in the present embodiment, the number of communication slots 21 is 8. Of course, in other embodiments, the number of the communication grooves 21 may be 2, 3, 4, 5, 6, or the like.
Referring to fig. 1, 3 and 8, in certain embodiments, the flow path selection valve 10 includes a second spool 28 disposed on the manifold 24, the first spool 26 being disposed on the second spool 28, the second spool 28 being provided with a first passage 30, a second passage 32 and a third passage 34, the first passage 30 being in communication with the first port 18, the second passage 32 being in communication with the second port 20, the third passage 34 being in communication with the common port 16,
the communication groove 21 communicates the first passage 30 and the second passage 32 to communicate the first port 18 and the second port 20 in the case where the flow path selection valve 10 is in the first valve position, and the communication groove 21 communicates the first passage 30 and the third passage 34 to communicate the first port 18 and the common port 16 in the case where the flow path selection valve 10 is in the second valve position.
As such, the first spool 26 selectively communicates the first port 18 with the common port 16, or the first port 18 and the second port 20, via the second spool 28, which facilitates preparation of a flow through the selector valve.
Specifically, the second spool 28 is square, and the volumes of both the first spool 26 and the second spool 28 are smaller than the volume of the manifold 24. Because the manifold 24 and the first valve spool 26 are manufactured separately, the accuracy of both may not be such that the manifold 24 and the first valve spool 26 meet the fit requirements and liquid leakage occurs. Since the shapes of the first spool 26 and the second spool 28 are relatively regular, manufacturing is easy. Accordingly, embodiments of the present application may allow the flow path selection valve 10 to be more easily manufactured and more stable by connecting the manifold 24 and the first spool 26 through the second spool 28.
Of course, in other embodiments, the second spool 28 may be omitted. At this time, the first spool 26 is cooperatively connected with the manifold 24.
In the present embodiment, the first channel 30, the second channel 32 and the third channel 34 are all independent channels, and the channels are separately arranged. The first passage 30, the second passage 32, and the third passage 34 are all linear, and each penetrate the second spool 28 in the thickness direction of the second spool 28.
Of course, in other embodiments, at least one of the first, second and third channels 30, 32, 34 may be bent, curved, etc., without limiting the specific shape of the first, second and third channels 30, 32, 34 herein.
In the present example, the number of first passages 30 is 8 as well as the number of first ports 18. The number of second passages 32 is the same as the number of second ports 20, and is 8. The number of third channels 34 is 8. Of course, in other embodiments, the number of first, second, and third channels 30, 32, 34 may be 2, 3, 4, 5, 6, etc. other numbers.
As in the example of fig. 8, the first, second and third passages 30, 32 and 34 are arranged in a matrix, 8 first passages 30, 8 second passages 32 and 8 third passages 34 are all arranged at intervals along the length direction of the second spool 28, and 8 first passages 30 are arranged along a first straight line, 8 second passages 32 are arranged along a second straight line, and 8 third passages 34 are arranged along a third passage 34. The first passages 30 are aligned with the third passages 34 one by one in the width direction of the second spool 28, and the first passages 30 and the second passages 32 are offset from each other.
Of course, in other embodiments, the first channel 30, the second channel 32, and the third channel 34 may be arranged in other manners, and the arrangement of the first channel 30, the second channel 32, and the third channel 34 is not limited herein.
In the embodiment of the present application, the second valve element 28 is fixedly disposed with respect to the manifold 24. The first spool 26 slides relative to the second spool 28 on the surface of the second spool 28 such that the first spool 26 can slide between the first position and the second position such that the communication groove 21 can selectively communicate the first passage 30 and the second passage 32, or the first passage 30 and the third passage 34.
Referring to fig. 3 and 4, in some embodiments, the manifold 24 is provided with a cavity 36, and the second valve spool 28 is at least partially received in the cavity 36. In this way, the manifold 24 and the second valve spool 28 cooperate more compactly, which may reduce the volume of the flow path selector valve 10, facilitating miniaturization of the flow path selector valve 10.
Specifically, the shape of the cavity 36 is adapted to the shape of the second valve element 28, and in the embodiment of the present application, the shape of the cavity 36 is also rectangular. As shown in fig. 3, the second valve spool 28 is partially received within the cavity 36, or a portion of the second valve spool 28 protrudes from the cavity 36.
Referring to fig. 4, in some embodiments, a bottom surface of the cavity 36 is provided with a first connection port 38, a second connection port 40, and a third connection port 42. The first connection port 38 communicates with the first port 18 and the first passage 30. The second connection port 40 communicates the second port 20 with the second passage 32. The third connection port 42 communicates the common port 16 and the third channel 34.
In this way, the second valve element 28 communicates with the first port 18, the second port 20 and the common port 16 through the connection port provided at the bottom surface of the chamber 36, so that the contact area between the second valve element 28 and the chamber 36 can be increased, and liquid leakage can be prevented.
In order to enable the first connection port 38 to be in butt joint with the first channel 30, the second connection port 40 to be in butt joint with the second channel 32, and the third connection port 42 to be in butt joint with the third channel 34, the arrangement manners of the first connection port 38, the second connection port 40 and the third connection port 42 are the same as those of the first channel 30, the second channel 32 and the third channel 34, and the arrangement manners of the first connection port 38, the second connection port 40 and the third connection port 42 are not repeated here.
Referring to fig. 4 and 5, in some embodiments, at least two of the first port 18, the second port 20, and the common port 16 are each located on a different side of the manifold 24. For example, the first port 18 and the second port 20 are located on the same side of the manifold 24, and the common port 16 is located on the other side of the manifold 24. As another example, the first port 18 and the common port 16 are on the same side of the manifold 24 and the second port 20 is on the other side of the manifold 24. For another example, the first port 18, the second port 20, and the common port 16 are each located on a different side of the manifold 24.
In the azimuthal illustration of fig. 5, the first port 18 is located on the left side of the manifold 24, the second port 20 is located on the bottom side of the manifold 24, and the common port 16 is located on the right side of the manifold 24. In this way, the ports are disposed on different sides of the manifold 24, so that the space of the manifold 24 can be fully utilized, so that the manifold 24 is more miniaturized, and the manifold 24 can be conveniently connected with other parts.
Referring to fig. 7, in some embodiments, the communication groove 21 includes a first communication groove 22 and a second communication groove 23 disposed at intervals. With the flow path selection valve 10 in the first valve position, the first port 18 and the second port 20 communicate through the first communication groove 22, as shown in fig. 9. With the flow path selection valve 10 in the second valve position, the first port 18 communicates with the common port 16 through the second communication groove 23, as shown in fig. 10. Alternatively, the communication slot 21 includes two discrete portions, which may facilitate control of the communication of the first port 18 with the second port 20, and the communication of the first port 18 with the common port 16, by the communication slot 21.
Arrows in fig. 9 and 10 represent the fluid direction of the liquid. As in fig. 9, after entering the flow path selection valve 10 from the second port 20, the liquid flows out from the first port 18 after passing through the second passage 32, the first communication groove 22, and the first passage 30 in this order.
In fig. 10, after the liquid enters the flow path selection valve 10 from the common port 16, the liquid passes through the third passage 34, the second communication groove 34, and the first passage 30 in this order, and then flows out from the first port 18.
As in the example of fig. 7, to accommodate the arrangement of the first passage 30, the second passage 32, and the third passage 34, the first communication groove 22 extends in a straight line obliquely with respect to the width direction of the first spool 26, and the second communication groove 23 extends in a straight line along the width direction of the first spool 26.
It is understood that fig. 7 is only one example of the first communication groove 22 and the second communication groove 23. In other embodiments, the shapes of the first communication groove 22 and the second communication groove 23 may be arc-shaped, bent, or the like.
In other embodiments, one of the first communication groove 22 and the second communication groove 23 may be omitted, or the communication groove 21 may be a continuous groove. At this time, in one example, the first channel 30 may be disposed between the second channel 32 and the third channel 34, and the first channel 30, the second channel 32, and the third channel 34 may be arranged along the same straight line. The communication groove 21 has a straight line shape. When the first spool 26 is in the first position, one end of the communication groove 21 communicates with the first passage 30, and the other end communicates with the second passage 32, so that the first port 18 and the second port 20 communicate; when the second spool 28 is in the second position, one end of the communication groove 21 communicates with the third passage 34, and the other end communicates with the first passage 30, so that the common port 16 communicates with the first port 18.
Referring again to fig. 1 and 3, in some embodiments, the flow path selection valve 10 includes a drive member 56, the drive member 56 being configured to drive the first spool 26 to rotate or slide. In this manner, the drive member 56 may move the first spool 26 such that the first spool 26 may be positioned in different locations to enable the flow path selection valve 10 to perform different functions.
Specifically, the driving part 56 may provide electromagnetic driving. For example, the drive member 56 may be a motor having a lead screw configuration when the first valve spool 26 slides relative to the manifold 24, and the drive member 56 may be a motor having a rotating shaft when the first valve spool 26 rotates relative to the manifold 24.
Referring to fig. 1, 3 and 11, in some embodiments, the flow path selection valve 10 includes a slider 57 coupled to the first spool 26, the slider 57 coupled to a driving member 56, the driving member 56 driving the first spool 26 to slide via the slider 57. In this manner, the drive member 56 is facilitated to drive the first spool 26 to slide.
Specifically, the slider 57 is detachably connected with the first spool 26. For example, the slider 57 is connected to the first valve element 26 via a positioning pin 54, and the slider 57 is driven by a driving member 56, so that the slider 57 can slide the first valve element 26 via the positioning pin. Of course, the slider 57 and the first valve element 26 may be connected by a snap-fit structure or the like, and the present application is not limited to a specific connection manner of the slider 57 and the first valve element 26.
When the driving member 56 is a screw motor, the slider 57 may be sleeved on the screw of the screw motor. During rotation of the lead screw, the slider 57 may move relative to the lead screw, thereby urging the first spool 26 to move.
Referring to fig. 1 and 3, in certain embodiments, the flow path selection valve 10 includes a housing 58 removably coupled to the manifold 24, with the first spool 26 and slider 57 housed in the housing 58. In this way, the housing 58 can protect the first spool 26 and the slider 57, and provide pressing force to the first spool 26 and the second spool 28, avoiding the occurrence of liquid leakage failure of the first spool 26 and the second spool 28.
Specifically, the housing 58 may be coupled to the manifold 24 by fasteners 55. In one example, during assembly of the flow path selection valve 10, the second valve spool 28 is installed into the manifold 24, the first valve spool 26 is installed onto the second valve spool 28, the first valve spool 26 and the slider 57 are then restrained, the housing 58 is then covered onto the manifold 24 such that the slider 57 and the first valve spool 26 are both positioned within the housing 58, and finally the housing 58 is secured to the manifold 24 by fasteners 55 passing through the manifold 24 and tightening with the housing 58.
Referring to fig. 11 and 12, in some embodiments, the housing 58 is provided with a guide groove 59, and the slider 57 includes a connection portion 60 and a guide rail portion 61 connected to the connection portion 60. The connecting portion 60 is connected to the first spool 26. The guide rail portion 61 cooperates with the guide groove 59 to guide the slider 57 to slide the first spool 26. Thus, the guide rail portion 61 and the guide groove 59 cooperate to slide the slider 57 along a predetermined trajectory, thereby allowing the first spool 26 to slide between the first position and the second position.
Specifically, the connection portion 60 may be connected to the first spool 26 by the detent pin 54. The contour of the connection 60 may be adapted to the shape of the first spool 26 to facilitate connection with the first spool 26. The rail portion 61 protrudes from the surface of the connecting portion 60. The cross-sectional area of the rail portion 61 is smaller than the cross-sectional area of the connecting portion 60.
Referring to fig. 13, a flow cell assembly 101 according to an embodiment of the present application includes the flow path selection valve 10 according to any of the above embodiments and a flow cell 62, the flow cell 62 being connected to the flow path selection valve 10. The flow cell 62 includes a plurality of side-by-side passages 621, one end of the passages 621 communicating with the first port 18. In this manner, the flow path selection valve 10 and the flow cell 62 may form an integral module for ease of installation.
The flow cell 62 of the present application provides a biochemical reaction site, and the flow cell 62 may be a chip in particular, and the flow cell 62 is removably connected to the flow path selection valve 10. Specifically, the flow cell 62 may be provided with a plug formed with a passage 621, which plug may be inserted into the first port 18, thereby realizing a direct connection of the passage 621 of the flow cell 62 with the first port 18. Of course, in other embodiments, the flow cell 62 and the flow path selection valve 10 may be in communication via a conduit.
In some embodiments, the flow cell assembly 101 includes two flow path selection valves 10 and one flow cell 62, with one end of the passage 621 communicating with the first port 18 of one of the flow path selection valves 10 and the other end of the passage 621 communicating with the first port 18 of the other flow path selection valve 10.
In some embodiments, one or the other end of the passage 621 is in ductless connection with the first port 18. In this way, the flow cell 62 is directly connected to the flow path selector valve 10, and a connected pipe can be omitted, thereby reducing the risk of leakage.
Referring again to fig. 2, a fluid circuit system 12 embodying an embodiment of the present application includes the flow path selection valve 10, the pump 14, the plurality of flow paths 102, and the control circuit 63 of any of the above embodiments. A plurality of flow paths 102 are fluidly connected to flow cell 62 to support a target analyte when flow cell 62 is installed in fluid path system 12.
Pump 14 is fluidly connected to flow cell 62 when flow cell 62 is installed in fluid path system 12 and flows liquid through flow path 102 selected by flow path selection valve 10 during an analysis operation.
The control circuit 63 is operatively coupled to the flow path selection valve 10, the control circuit 63 having one or more processors and memory storing computer-executable instructions that, when executed by the processors, control the processors to command the flow path selection valve 10 to select a specified flow path 102.
In the liquid path system 12 according to the embodiment of the application, the flow path selection valve 10 can be used for independently or parallelly controlling the three-way paths 102, so that the simultaneous arrangement of a plurality of three-way valves in the liquid path system 12 can be avoided, thereby reducing the cost, the volume, the reagent consumption, the reliability and the maintenance and control of the liquid path system 12. The fluid path system 12 described above is particularly useful in systems requiring high precision in fluid control and delivery, such as sequencing systems.
Specifically, pump 14 may power fluid circuit system 12 such that fluid may flow. The number of pumps 14 may comprise a plurality, such as two, where one pump 14 may be in communication with the common port 16 and another pump 14 in communication with the second port 20, either split or co-current. The pump in communication with the common port 16 may provide power to the liquid from the common port 16 to the first port 18 and the pump in communication with the second port 20 may provide power to the liquid from the second port 20 to the first port 18.
In one embodiment, the number of first ports 18 is 8 and the pump 14 comprises 8 pumps equal in number to the number of first ports 18, such as a negative pressure eight-way pump located downstream of the fluid path system 12, and in particular downstream of the flow cell 62, the eight-way pump being capable of independently providing negative pressure to the fluid after passing through the flow path selection valve 10 such that the power level of each of the plurality of flow paths 102 can be independently controlled to facilitate fine control of the flow and/or velocity of each of the flow paths.
Referring to fig. 2, in an embodiment of the present application, the fluid path system 12 further includes a storage 64, the storage 64 may store a plurality of solutions, including a reaction solution, a buffer solution, a cleaning solution, and/or purified water, etc., and reagents including different reactions or different steps of a reaction, and the fluid path system 12 including the pump 14 may enable one or more solutions to flow toward the flow cell 62 sequentially or simultaneously.
In certain embodiments, the reservoir 64 includes a first reservoir 66 and a second reservoir 68, the first reservoir 66 carrying the biological sample solution and the second reservoir 68 carrying the reaction solution. With the flow path selection valve 10 in the first valve position, the flow path selection valve 10 communicates with the first reservoir 66 and the flow cell 62, and the pump 14 induces a flow of the biological sample solution toward the flow cell 62. With the flow path selection valve 10 in the second valve position, the flow path selection valve 10 communicates with the second reservoir 68 and the flow cell 62, and the pump 14 induces the reaction liquid to flow toward the flow cell 62 through the second flow passage.
That is, the flow path selection valve 10 may allow the reaction solution and the biological sample solution to enter the flow cell 62 independently and time-divisionally to sequentially perform the respective reactions, such as the sample loading reaction (immobilization and/or hybridization of nucleic acid) and the sequencing reaction.
Illustratively, the first reaction is, for example, an immobilization and/or hybridization reaction, i.e., immobilization or attachment of the nucleic acid to be measured to a channel or reaction region of the flow cell 62, and the biological sample solution is a solution containing the nucleic acid to be measured, which may be sequentially passed through the second port 20 and the first port 18 into the flow cell 62 to perform the first reaction. In one example, the flow cell 62 is a sandwich-like structure having upper, middle and lower layers, or a structure having upper and lower layers, the upper layer (adjacent to the objective lens) being a light-transmissive glass layer, the middle or lower layer being a light-transmissive glass layer or a light-opaque substrate layer, the middle or lower layer being provided with a plurality of channels arranged in an array capable of containing a liquid to provide a physical space for a reaction, each channel having independent liquid inlets and liquid outlets, the number of channels being equal to the number of first ports 18, a plurality of biological sample solutions being simultaneously and fluidically independently introduced into one channel of the flow cell 62 through one second port 20 and one first port 18, whereby the flow path selection valve 10 or the liquid path system 12 comprising the flow path selection valve 10 is capable of effecting loading and detection analysis of a plurality of biological samples without the need for combining other means (e.g., labeling different biological samples). Specifically, the flow cell 62 herein is, for example, a solid phase substrate having a functional group on the surface and/or a solid phase substrate having a probe attached to the surface, the solid phase substrate having a functional group on the surface and/or the solid phase substrate having a probe attached to the surface are also generally referred to as chips or microspheres, for example, a functional group is attached to the upper surface of a channel (lower surface of an upper glass layer) and/or the lower surface of a channel (upper surface of a middle layer or lower layer structure) or a probe (oligonucleotide) is attached thereto, and/or at least a part of the probe is complementarily paired with a nucleic acid to be detected to effect immobilization or attachment of the nucleic acid to the solid phase substrate surface for subsequent detection analysis, for example, sequencing reaction, of the nucleic acid to be detected immobilized or attached to the solid phase substrate surface.
The second reaction is, for example, a sequencing reaction, that is, a nucleic acid sequencing reaction, more specifically, a sequencing-by-synthesis reaction using a reversible terminator based on chip detection, and accordingly, the reaction solution includes one or more kinds of reagents including a substrate (reversible terminator), a polymerase catalyst, a cleavage reagent (radical cleavage reagent), an imaging reagent, and a washing reagent, and the like, and each reagent/reaction solution may sequentially or simultaneously enter the flow cell 62 through the common port 16 and the first port 18 to perform the second reaction, and in particular, the corresponding reagents may sequentially or simultaneously flow to the flow cell 62 after passing through the flow path selection valve 10 to perform a plurality of reaction steps in the flow cell 62 to achieve the so-called sequencing reaction; the flow cell 62 is, for example, a solid phase substrate having nucleic acid to be measured attached to the surface thereof, and the solid phase substrate having nucleic acid to be measured attached to the surface thereof is, for example, a chip or a microsphere.
The first reaction and the second reaction described above can be performed in the flow cell 62 by controlling one flow path selection valve 10 to switch the flow paths, and a nucleic acid sequencing system (integrated system) including the first reaction and the second reaction can be made to have a simpler structure. And thus the first reaction and the second reaction do not need to be carried out in different systems/devices/apparatuses, the user operation is simpler and more convenient, and the cost of constructing the integrated nucleic acid sequencing system is far lower than the sum of the cost of constructing a nucleic acid sequencing system (sample loading apparatus) which implements the first reaction alone and the cost of constructing a nucleic acid sequencing system which implements the second reaction alone.
The first reaction of an embodiment of the present application includes a reaction to attach biomolecules into the flow cell 62, including, for example, immobilization, hybridization, or sampling reactions. The biological molecules include DNA and/or RNA, etc., including ribonucleotides, deoxyribonucleotides and analogs thereof, including A, T, C, G and U and analogs thereof. Wherein C represents cytosine or a cytosine analogue, G represents guanine or a guanine analogue, A represents adenine or an adenine analogue, T represents thymine or a thymine analogue, and U represents uracil or a uracil analogue.
The second reaction includes a reaction for detecting a biomolecule, e.g., a nucleic acid, attached to the flow cell 62, which may be a sequencing reaction, commonly referred to as sequencing, including determining the primary structure or sequence of DNA or RNA, etc., including determining the nucleotide/base order of a given nucleic acid fragment. The second reaction may include one or more sub-reactions. In one example, the DNA is sequenced, the second reaction is sequencing, sequencing-by-synthesis or sequencing-by-ligation, specifically, for example, sequencing-by-synthesis using engineered nucleotides with detectable labels, such as dntps or dNTP analogs with detectable labels, based on chip detection, the sequencing comprising a plurality of sub-reactions including base extension reactions, signal collection, and cleavage of a detection group to effect the determination of the base type at one position on the nucleic acid sequence to be tested; performing the plurality of sub-reactions once, which may be referred to as performing a repeat reaction or a round of reaction, sequencing includes a plurality of repeat reactions or rounds of reactions to determine the nucleotide/base order of reading at least a portion of the sequence of the nucleic acid molecule (template). The modified nucleotide is said to carry a fluorescent molecule which in a specific context is capable of being excited to fluoresce for detection by an optical system, and which modified nucleotide tag, when bound to a nucleic acid to be detected, is capable of preventing base/nucleotide binding to the next position of the nucleic acid to be detected, for example a dNTP with a chemically cleavable moiety at the 3' hydroxyl end or a dNTP with a molecular conformation which is capable of preventing the next nucleotide binding to the nucleic acid to be detected, the dNTP or dNTP analogue being four deoxyribonucleotides comprising bases A, T/U, C and G respectively.
For sequencing-by-synthesis (SBS) or sequencing-by-ligation (SBL) based on chip detection, the base extension reaction comprises binding a nucleotide (including engineered nucleotides) to a nucleic acid molecule to be detected based on the base complementation principle on a flow cell 62 immobilized with the nucleic acid molecule to be detected under the action of a polymerase or ligase, and collecting the corresponding nucleic acid moleculesIs a reaction signal of (a). The engineered nucleotide may be a nucleotide with a detectable label that allows the engineered nucleotide to be detected in certain circumstances, such as a nucleotide with a fluorescent molecular label that fluoresces upon excitation by a laser of a particular wavelength; typically, for SBS, the engineered nucleotide also has the function of inhibiting the binding of additional nucleotides to the next position of the same nucleic acid molecule, e.g., with blocking groups that prevent the binding of additional nucleotides to the next position of the template, such that each extension reaction is a single base extension reaction to enable the acquisition of a corresponding signal from a sub single base extension, e.g., an engineered azido (-N) group attached to the 3 'position of the nucleotide's sugar group 3 )。
Detection and analysis of biomolecules, typically, biomolecules are first attached to flow cell 62 and then biomolecules attached to flow cell 62 are detected; specifically, in any of the above embodiments, the first reaction is performed before the second reaction, i.e., the sequencing reaction is performed after the nucleic acid to be tested is attached to the flow cell 62. Thus, with the liquid path system 12, a variety of reactions can be performed including sampling and sample detection in one nucleic acid sequencing system.
In certain embodiments, the first reaction is a sampling reaction and the second reaction is a sequencing reaction, the first reaction is performed before the second reaction is performed, and the nucleic acid molecule to be tested is contained in a trace biological sample solution, for example, on the order of microliters, for example, 20 microliters; prior to the first reaction, the liquid circuit system 12 has been purged with a purging solution, such as a solution that does not affect subsequent reactions, and the liquid circuit system 12 is filled with a purging solution; before the first reaction is started, a section of air is injected to separate the biological sample solution flowing into the flow cell and the cleaning solution in the liquid path system, so as to prevent the trace biological sample from being diffused and/or diluted, influence the connection of the nucleic acid molecules to be detected to the flow cell 62 and the subsequent detection of the nucleic acid molecules to be detected, and separate the biological sample solution flowing into the flow cell and the cleaning solution in the liquid path system, so that the sample injection condition is also facilitated to be observed, and the flow cell 62, for example, whether a chip comprising a plurality of channels is normal, whether the liquid path system 12 is normal or not is facilitated to be observed.
The substrate may be any solid support useful for immobilizing nucleic acid sequences, such as nylon membranes, glass sheets, plastics, silicon wafers, magnetic beads, and the like. Probes, which may be a stretch of DNA and/or RNA, or the like, may be randomly distributed on the surface of the substrate, and may also be referred to as primers, capture strands, or immobilized strands. The first reaction may fixedly attach the biomolecules to the probes, for example based on the base complementarity principle, such that the biomolecules are attached to the flow cell 62.
Collecting the signal includes collecting a signal emitted from the engineered nucleotide bound to the nucleic acid molecule, for example, by laser irradiation of a specific region in the flow cell 62 after the base extension reaction using an optical imaging assembly/system, the fluorescent molecular markers in the specific region being excited to fluoresce, and further photographing/image-collecting the region to record the biochemical reaction signal as image information. Sequencing in turn involves converting the image information obtained from multiple rounds/iterations of the reaction into sequence information, i.e., determining the base type, commonly known as base-recognition (base-sequencing), based on the image information.
Radical excision involves removal of the detectable label and/or blocking group attached to the engineered nucleotide of the nucleic acid molecule after the base extension reaction, so that other nucleotides (including the engineered nucleotide) can be attached to the next position of the nucleic acid molecule for the next repeat reaction or round of reaction.
A wash reagent may also be introduced after the completion of the previous round or previous sub-reaction or step and before the start of the next round or next sub-reaction or step to remove unreacted materials, materials that interfere with the reaction or signal acquisition, remaining in the flow cell 62 or in the fluid path system 12.
In certain embodiments, the flow path selection valve 10 is disposed upstream of the flow cell 62. In this way, the flow path selector valve 10 can control the solution to enter the flow cell 62, and the liquid path system 12 can control the inlet and outlet of various solutions to realize various reactions by only adopting one power component (such as a pump) or only providing one direction of power, thereby being beneficial to further reducing the volume of the liquid path system 12 and improving the integration degree thereof and being beneficial to industrialization.
In some embodiments, pump 14 is disposed downstream of flow cell 62, providing negative pressure. In this manner, pump 14 may create a negative pressure on flow cell 62 and flow path selection valve 10, etc., thereby allowing solution to enter flow cell 62. In addition, the negative pressure created by pump 14 removes air from flow cell 62, avoiding air from affecting the proper reaction of flow cell 62. The fluid path system 12 comprising the pump 14 downstream of the flow cell 62 is capable of providing a uniform power direction for the incoming and outgoing fluids of a plurality of types of reactions, and is particularly suitable for a fluid path system 12 comprising pressure sensitive elements/components, e.g. the flow cell 62 is a chip comprising thin glass and having a multi-layer sheet structure bonded by adhesive, which may further comprise a plurality of independent reaction zones/channels, wherein the power/pressure direction changes are liable to deform the chip or cause fluid leakage or channeling.
Referring to fig. 14, in some embodiments, the flow cell 62 includes a first flow cell 70 and a second flow cell 72, and the flow path selector valve 10 includes a first flow path selector valve 74 and a second flow path selector valve 76, the first flow path selector valve 74 and the second flow path selector valve 76 being in communication with the first flow cell 70 and the second flow cell 72, respectively. In this way, the first flow path selection valve 74 and the second flow path selection valve 76 can independently control the reactions of the first flow cell 70 and the second flow cell 72, which is beneficial for the first flow cell 70 and the second flow cell 72 to perform different reactions or different steps/sub-reactions of the same reaction in a staggered manner, and improves the reaction efficiency. In addition, the fluid path system 12 including the flow path selection valve 10, in combination with the plurality of flow cells 62 or flow cells 62 having a plurality of independent reaction regions, facilitates improved detection throughput and/or enables detection of multiple samples at one time.
Specifically, the first flow cell 70 and the second flow cell 72 may be separate structures or may be integrally formed. In the example shown in fig. 14, the first flow cell 70 and the second flow cell 72 are of unitary construction. The first flow cell 70 and/or the second flow cell 72 may include one or more reaction zones. Wherein each reaction zone may effect a reaction, and the reaction zones may be intersecting, continuous or separate zones.
As in the example of fig. 14, the first flow cell 70 includes eight first reaction regions 78. Eight first reaction zones 78 are in one-to-one correspondence with eight first ports 18 of the first flow path selection valve 74. Eight first reaction zones 78 are provided separately. Similarly, the second flow cell 72 includes eight second reaction regions 80. Eight second reaction zones 80 are in one-to-one correspondence with eight second ports of the second flow path selection valve 76. Eight second reaction zones 80 are provided separately.
It should be noted that the first flow path selector valve 74 and the second flow path selector valve 76 may operate simultaneously, or may operate separately or alternatively, so that the reactions or steps in the first flow cell 70 and the second flow cell 72 may be performed in a time-sharing and staggered manner, which is beneficial to improving the reaction efficiency and saving the consumption of detection reagents and/or time.
Referring to fig. 15, in some embodiments, fluid path system 12 includes a reagent selection valve 84 and flow cell 62, reagent selection valve 84 selecting a reagent from a plurality of reagents according to an analytical protocol. The flow path selection valve 10 is fluidly connected between the reagent selection valve 84 and the flow cell 62, the flow path selection valve 10 being adapted to select a flow path through the flow cell 62 from a plurality of flow paths through the flow cell 62 according to an analysis protocol and to direct the selected reagent through the flow cell 62. The pump 14 flows the selected reagents through the selected flow paths according to an analytical protocol.
Specifically, the reagent selector valve 84 is provided with a plurality of liquid inlets 86 and a liquid outlet 88, the liquid outlet 88 being selectively communicated with one of the liquid inlets 86, the liquid inlet 86 being communicated with the reagent selector valve 82. In this manner, the multiple inlets 86 of the reagent selector valve 84 allow the flow cell to enter different liquids, thereby achieving multiple rounds/repetitions of the reaction.
As shown in fig. 15, in some embodiments, the fluid path system 12 includes a fluid trap 89, the fluid trap 89 collecting fluid exiting the flow cell 62. For example, the liquid trap 89 collects the liquid after the first reaction and the second reaction.
To sum up, in one embodiment of the present application, the fluid circuit system 12 includes a flow path selection valve 10, a pump 14, a plurality of flow paths 102, and a control circuit 63. The flow path selector valve 10 includes a manifold 24 and a first spool 26. The manifold 24 is provided with a common port 16, a plurality of first ports 18, and a plurality of second ports 20. The first spool 26 is provided with a communication groove 21. The first spool 26 may be rotated or slid relative to the manifold 24 to switch the flow path selection valve 10 between the first valve position and the second valve position. With the flow path selection valve 10 in the first valve position, the first port 18 and the second port 20 communicate through the communication groove 21. With the flow path selection valve 10 in the second valve position, the first port 18 communicates with the common port 16 through the communication groove 21. A plurality of flow paths 102 are fluidly connected to flow cell 62 to support a target analyte when flow cell 62 is installed in fluid path system 12. Pump 14 is fluidly connected to flow cell 62 when flow cell 62 is installed in fluid path system 12 and flows liquid through flow path 102 selected by flow path selection valve 10 during an analysis operation. The control circuit 63 is operatively coupled to the flow path selection valve 10, the control circuit 63 having one or more processors and memory storing computer-executable instructions that, when executed by the processors, control the processors to command the flow path selection valve 10 to select a specified flow path 102.
Referring to fig. 15, the embodiment of the present application further provides a sequencing system 90, for example, a nucleic acid determining system, and the sequencing system 90 includes the liquid path system 12 according to any of the above embodiments.
In one example, the control circuit 63 is configured to control the flow path selection valve 10 to rotate to a first valve position to communicate the first reservoir 66 with the flow cell 62, the first reservoir 66 carrying a first reaction liquid comprising nucleic acid molecules; and configured to pass the first reaction liquid into the flow cell 62 with the flow path selection valve 10 in the first valve position to perform a first reaction, the first reaction comprising ligating at least a portion of the nucleic acid molecules to the flow cell 62; and is configured to rotate the flow path selection valve 10 to a second valve position to communicate the second reservoir 68 with the flow cell 62, the second reservoir 68 carrying a second reaction liquid containing components required for performing nucleic acid sequencing; and is configured to pass a second reaction solution through the second flow path into the flow cell 62 with the flow path selection valve 10 in the second valve position to perform a second reaction, the second reaction comprising causing a nucleic acid molecule in the flow cell 62 after performing the first reaction to interact with the second reaction solution to undergo a polymerization reaction and detecting a signal from the reaction to effect sequencing of the nucleic acid molecule. The sequencing system 90 of the present application is, for example, a sequencer or a sequencing platform.
In one example, the first reservoir 66 carries a biological sample solution comprising nucleic acid molecules, the second reservoir 68 carries a reaction solution comprising components necessary to perform a polymerization reaction, the control circuit 63 is configured to flow path selection valve 10 to cause the biological sample solution in the first reservoir 66 to enter the flow cell 62 to perform a first reaction comprising at least a portion of the nucleic acid molecules connected to the flow cell 62, and the control circuit 63 is configured to control the flow path selection valve 10 to cause the reaction solution in the second reservoir 68 to enter the flow cell 62 to perform a second reaction after the first reaction has been performed, the second reaction comprising the interaction of the nucleic acid molecules in the flow cell 62 with the reaction solution to effect the polymerization reaction.
The sequencing system 90 operates according to commands that implement a prescribed protocol for testing, validation, analysis (e.g., including sequencing), and the like. The prescribed protocol will be pre-established and include a series of events or operations for the activity, such as aspirating reagents, aspirating air, aspirating other fluids, spraying such reagents, air and fluids, and the like. This protocol will allow for coordination of such fluid operations with other operations of the instrument, such as reactions occurring in flow cell 62, imaging of flow cell 62 and its sites, and the like.
The present application also provides a system comprising a sequencing system 90 according to any of the embodiments above.
The present application also provides a method of controlling a system to perform sequencing, the system may be the above fluid path system 12, for example, the system comprising a plurality of flow paths 102, a flow cell 62 coupled to the plurality of flow paths 102, a flow path selection valve 10, a pump 14, a first reservoir 66, and a second reservoir 68. The flow path selector valve 10 includes a manifold 24 and a first spool 26. The manifold 24 is provided with a common port 16, a plurality of first ports 18, and a plurality of second ports 20. The first spool 26 is provided with a communication groove 21. The first spool 26 may be rotated or slid relative to the manifold 24 such that the communication slot 21 selectively communicates the common port 16 with the first port 18 or the first port 18 with the second port 20 to select different flow paths. The first memory 66 is connected to the second port 18. The second memory 68 is connected to the common port 16. The first reservoir 66 carries a first reaction liquid containing nucleic acid molecules. The second reservoir 68 carries a second reaction liquid containing components necessary for nucleic acid sequencing. The pump 14 is used to flow the liquid through the flow path selected by the flow path selection valve 10.
Referring to fig. 16, the method includes: s110, switching the flow path selection valve 10 to the first valve position so that the communication groove 21 communicates with the first port 18 and the second port 20 to communicate with the first reservoir 66 and the flow cell 62; s120, with the flow path selection valve 10 in the first valve position, controlling the pump 14 to operate to allow the first reaction liquid to enter the flow cell 62 to perform a first reaction, the first reaction including connecting at least a portion of the nucleic acid molecules to the flow cell 62; s130, switching the flow path selection valve 10 to the second valve position so that the communication groove 21 communicates the first port 18 and the common port 16 to communicate the second reservoir 68 and the flow cell 62; s140, with the flow path selection valve 10 in the second valve position, controlling the pump 14 to operate so that the second reaction liquid enters the flow cell 62 to perform the second reaction, the second reaction including causing the nucleic acid molecules in the flow cell 62 after the first reaction to interact with the second reaction liquid to undergo polymerization reaction and detecting a signal from the reaction, to effect sequencing of the nucleic acid molecules.
The method realizes the first reaction and the second reaction by switching different flow channels/reagents by setting one flow path selection valve 10 at different valve positions, and is particularly suitable for the operation control of a system or equipment with high integration level.
Current second generation high throughput sequencing platforms or single molecule sequencing platforms generally require processing of the sample to be sequenced prior to on-machine sequencing, e.g., to adapt a designated sequencing platform, processing the sample to be sequenced to a library adapted to the sequencing platform, and loading the library into a designated area, e.g., flow cell 62, to place the flow cell 62 containing the sample to be sequenced into a sequencer for automated sequencing. Currently commercially available sequencing platforms, the processing of the sample to be tested prior to the on-board sequencing is typically separate from the on-board sequencing, e.g., sample processing/library preparation in a reagent tube manually, or processing and loading of the sample to be tested on sample processing equipment. The method can realize sample processing and sequencing before the machine, and can realize switching and in-out control of different flow channels of various reagents by enabling the flow path selection valve 10 to be positioned at different valve positions, thereby being particularly suitable for an integrated sequencing platform integrating the functions of sample processing and sequencing before the machine.
Referring to fig. 17, in some embodiments, the system further comprises a third reservoir 104, the third reservoir 104 being connected to the common port 16, the third reservoir 104 carrying a third reaction solution comprising components required for performing the amplification. The method further comprises, after performing step S120 and before S140 (after performing the first reaction and before performing the second reaction), performing the following: the pump 14 is controlled to operate to allow the third reaction liquid in the third reservoir 104 to enter the flow cell 62 to perform a third reaction, which includes allowing the nucleic acid molecules in the flow cell 62 after the first reaction to interact with the third reaction liquid to effect amplification of the nucleic acid molecules.
By "amplifying" is meant cloning a nucleic acid molecule, e.g., replicating the nucleic acid molecule into thousands or even millions of copies by polymerase chain reaction, into a cluster, any of which is identical to the sequence of the original nucleic acid molecule, such that the signal from the nucleic acid molecule can be amplified by increasing the number of molecules, facilitating detection of the nucleic acid molecule; in particular, in subsequent sequencing, the thousands of millions of molecules (clusters) emit signals equivalent to those from the single nucleic acid molecule, greatly enhancing the signal of the molecule, facilitating detection.
The current market of second generation high throughput sequencing platforms, such as ILLUMINA sequencing platform, ion Torrent sequencing platform and warrior gene sequencing platform, all require amplification of the signal from the molecule to be detected by amplification such as bridge PCR or rolling circle amplification, etc., before sequencing, so as to obtain a stronger signal that is easily identifiable for detection (or is not easily disturbed).
Referring to fig. 17, in some embodiments, the system further includes a fourth reservoir 106, the fourth reservoir 106 being connected to the common port 16, the fourth reservoir carrying a wash solution. The method further comprises performing, prior to performing step S120 (prior to performing the first reaction): with the flow path selection valve 10 in the first valve position, the pump 14 is controlled to operate to admit the wash solution in the fourth reservoir 106 into the flow cell 62. In this manner, the wash solution may rinse the flow cell 62, avoiding subsequent contamination of the first reaction solution with the last residual material and/or reducing unnecessary loss of the first reaction solution, e.g., trace amounts of biological sample solution (e.g., filling the tubing of the fluid path system 12).
In certain embodiments, the method further comprises, prior to performing step S120 (prior to the first reaction), the steps of: with the flow path selection valve 10 in the first valve position, the pump 14 is controlled to operate to vent air to the flow cell 62. Thus, prior to initiation of the first reaction, a segment of air is injected to separate the subsequently flowing first reaction solution from the wash solution already in the fluid path system, so as to prevent diffusion and/or dilution of the trace biological sample, thereby affecting the attachment of the nucleic acid molecules to be detected to the flow cell 62 and subsequent detection of the nucleic acid molecules to be detected.
In certain embodiments, the method further comprises performing the following steps prior to performing step S120 and/or prior to performing step S140 (prior to performing the first reaction and/or prior to performing the second reaction): pump 14 is controlled to operate to admit the wash solution in fourth reservoir 106 into flow cell 62. In this manner, the wash solution may wash the flow cell 62 and may prevent subsequent first and/or second reaction fluids from being affected by the last reaction or last step residues.
In certain embodiments, flow cell 62 has a solid support surface on which a first sequencing primer is immobilized, at least one end of the nucleic acid molecule comprising at least a portion of a sequence capable of complementary pairing with at least a portion of the first sequencing primer, and the first reaction comprises complementarily pairing at least a portion of the nucleic acid molecule with the first sequencing primer for ligation into flow cell 62.
The term "first sequencing primer" is an oligonucleotide (a short sequence of known nucleic acid sequences) that is immobilized on the surface of a chip, often also referred to as a "probe".
In certain embodiments, the second reaction solution comprises a first nucleotide, a first polymerase, and a cleavage reagent, step S140 comprises: (a) Controlling the pump 14 to operate to bring a first nucleotide and a first polymerase into the flow cell 62, and subjecting the flow cell 62 to conditions suitable for polymerization to bind the first nucleotide to the nucleic acid molecule by extending the first sequencing primer, the first nucleotide comprising a base, a sugar unit, a cleavable blocking group, and a detectable label; (b) Exciting the detectable label and collecting a signal from the detectable label; (c) Controlling the pump 14 to operate to pass a cleavage reagent into the flow cell 62 to remove the cleavable blocking group and the detectable label of the first nucleotide; (d) repeating (a) - (c) at least once.
In particular, so-called "placed under conditions suitable for polymerization" generally refers to temperature conditions in addition to the components/reagents required for polymerization (e.g., polymerase, reaction substrates, i.e., nucleotides, and/or sequencing primers). For example, the nucleic acid sequencing system 90 also includes a temperature control system that controls the temperature of the flow cell 62/reaction chamber to achieve "conditions suitable for polymerization".
The detectable label is, for example, an optically detectable label, such as a fluorescent molecule. The cleavable blocking group may prevent/inhibit binding of the other nucleotide (first nucleotide) in the reaction system to the next position of the nucleic acid molecule to be tested, and may be a physical blocking of, for example, a sugar group with an azide (-N) at the 3' position 3 ) It is also possible that the blocking group is not physically blocked (virtually blocked), for example, in the extension reaction solution system, to form a steric conformation which prevents the extension reaction from proceeding.
In certain embodiments, the second reaction solution further comprises a second nucleotide, step S140 further comprising, after (a), performing the following: controlling the pump 14 to operate to admit the second nucleotide and the first polymerase into the flow cell, and subjecting the flow cell to conditions suitable for polymerization to bind the second nucleotide to the nucleic acid molecule by continuing to extend the product of (a), the second nucleotide comprising a base, a sugar unit and a cleavable blocking group. Compared with the first nucleotide, the second nucleotide is a reversible terminator without a detectable label, and for the same polymerase, the reaction efficiency of the second nucleotide is generally higher than that of the first nucleotide, and the step is favorable for synchronizing the reactions of a plurality of nucleic acid molecules in one cluster, namely, the nucleic acid molecules with leading reaction (prephasing) or lagging reaction (phasing) in one cluster can be eliminated or reduced to a certain extent, so that the sequencing reaction is favorable.
Referring to FIG. 19, in certain embodiments, the second reaction solution comprises a third nucleotide, a fourth nucleotide, a second polymerase, a third polymerase, a cleavage reagent, and a second sequencing primer, at least one end of the nucleic acid molecule comprises at least a portion of a sequence capable of complementary pairing with at least a portion of the second sequencing primer, and controlling the pump 14 to operate to pass the second reaction solution through the second flow channel into the flow cell 62 to perform the second reaction comprises: (i) Controlling the pump 14 to operate to bring a third nucleotide and a second polymerase into the flow cell 62 and subjecting the flow cell 62 to conditions suitable for polymerization to bind the third nucleotide to the nucleic acid molecule by extension of the first sequencing primer to obtain a nascent strand, the third nucleotide being a nucleotide bearing neither a cleavable blocking group nor a detectable label; (ii) Controlling the pump 14 to operate to bring a fourth nucleotide, a third polymerase and a second sequencing primer into the flow cell 62, and subjecting the flow cell 62 to conditions suitable for polymerization to bring the second sequencing primer into engagement with the nascent strand and to bind the fourth nucleotide to the nascent strand by extending the second sequencing primer, the fourth nucleotide comprising a base, a sugar unit, a cleavable blocking group and a detectable label; (iii) Exciting the detectable label and collecting a signal from the detectable label; (iv) Controlling the pump 14 to operate to pass a cleavage reagent into the flow cell 62 to remove the cleavable blocking group and the detectable label of the fourth nucleotide; (v) repeating (ii) - (iv) at least once. Thus, a second reaction can be effected by steps (ii) - (v), effecting the determination of the nucleic acid molecule sequence.
The third nucleotide may be, for example, a natural nucleotide; the fourth nucleotide may be identical to the first nucleotide; the first to third polymerases may be the same or different, e.g., are different types of DNA polymerases or different mutants of the same type of DNA polymerase, each independently being effective to catalyze the performance of a specified extension/polymerization reaction in combination with a specified nucleotide.
Compared with the sequencing method in the previous embodiment, the method can measure and read the sequence of the other end of the nucleic acid molecule to be tested by synthesizing the complementary strand of the nucleic acid molecule to be tested, thereby realizing the sequencing of the other end of the nucleic acid molecule to be tested.
Similarly, in certain embodiments, the second reaction solution further comprises a fifth nucleotide, the method further comprising, after (ii), controlling the pump 14 to operate to enter the fifth nucleotide and the third polymerase into the flow cell, and subjecting the flow cell to conditions suitable for polymerization to bind the fifth nucleotide to the nascent strand by continuing to extend the product of (ii), the fifth nucleotide comprising a base, a sugar unit, and a cleavable blocking group. The fifth nucleotide, such as the second nucleotide, is a reversible terminator without a detectable label, and the step is performed in favor of a plurality of nucleic acid molecules in one cluster being in a synchronous reaction state, i.e. a nucleic acid molecule with reaction leading (prephasing) or lagging (phasing) in one cluster can be eliminated or reduced to a certain extent, which is in favor of sequencing reaction and longer reads (reads) can be obtained.
It should be noted that the explanation of the technical features of the structure, connection relation, and operation control of the flow path selection valve 10 and/or the liquid path system 12 in the above embodiments is also applicable to the method for implementing sequencing by the control system of any of the embodiments, and how to implement sequencing by the flow path selection valve 10 and the related elements/structural components of the control system of any of the embodiments, which is not developed herein, and the present exemplary description of the sequencing method by the structure, connection relation, function, and operation mode of the flow path selection valve 10 and/or the liquid path system 12 in the above embodiments is understood by those skilled in the art, so that the corresponding sequencing method can be implemented by using and controlling the flow path selection valve 10 and/or the liquid path system 12 and/or the sequencing system 90 in the above embodiments.
The application also provides a method comprising the method of the control system of any of the above embodiments to effect sequencing.
In the description of the present specification, reference to the terms "certain embodiments," "one embodiment," "some embodiments," "an exemplary embodiment," "an example," "a particular example," or "some examples" means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
Logic and/or steps represented in the flowcharts or otherwise described herein, e.g., a ordered listing of executable instructions for implementing logical functions, can be embodied in any computer-readable storage medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. For the purposes of this description, a "computer-readable storage medium" can be any means that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device.
In addition, each functional unit in each embodiment of the present invention may be integrated into one processing module, each unit may exist alone physically, or two or more units may be integrated into one module. The integrated modules may be implemented in hardware or in software functional modules. The integrated modules may also be stored in a computer readable storage medium if implemented in the form of software functional modules and sold or used as a stand-alone product.
Although embodiments of the present application have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the application, and that variations, modifications, alternatives and variations may be made to the above embodiments by those skilled in the art within the scope of the application, which is defined by the claims and their equivalents.