Flow path system, gene sequencer, and reagent recovery method

Abstract

A flow path system, a gene sequencer, and a reagent recovery method. The flow path system includes at least two reagent storage containers, a flow cell, a diversion module, and a fluid power unit. The flow cell is connected to the at least two reagent storage containers. The diversion module includes a diversion structure and at least two diversion channels. The fluid power unit is connected to the diversion module, the fluid power unit is selectively communicated with one of the at least two diversion channels, the fluid power unit is configured to drive reagents in a forward flow from the reagent storage containers to the diversion module, and the fluid power unit is further configured to drive reagents in a reverse flow from the diversion module to the reagent storage containers.

Description

[Technical Field]

[0001] The present application relates to a flow path system, a gene sequencer, and a reagent recovery method. [Background technology]

[0002] (background)

[0002] Various testing instruments (e.g., gene sequencers, flow cytometers, and high-pressure liquid chromatographs) used in clinical diagnostics and life science research typically have fluid systems for transferring various solutions between multiple regions. For example, samples containing test objects (e.g., cells, DNA fragments), biochemical reagents reacting with the samples, various buffers, washing solutions, etc. are generally transferred from sample tubes, reagent cells, and other containers to one or more reaction or testing regions, and then transferred to a waste region after the reaction or testing is completed. The concentration and homogeneity of the reagents entering the reaction region determine the efficiency of the biochemical reaction, and the former are closely related to the overall design of the fluid system. In addition, samples and biochemical reagents are often precious and expensive, which means that the amount of reagents used during transfer must be sufficiently small.

[0003]

[0003] Currently, most fluid systems in high-end testing equipment employ a pressure-driven configuration, using high-precision, low-internal-volume pump-valve components and conduits to fluidly connect the above-mentioned reagent storage area, reaction or testing area, waste area, and other areas. Biochemical reactions are often performed in stages, requiring various reagents to pass through the reaction areas sequentially, which poses the problem of displacement between reagents. Flow in a closed conduit or channel (also known as Poiseuille flow) results in a parabolic distribution of overall velocity due to the viscosity of the fluid, with low flow velocities near the walls and high flow velocities farther from the walls. Therefore, when one reagent in a portion of the conduit is displaced or swept away by a subsequent reagent, the reagent in the region near the wall is often more difficult to displace. As a result, it is necessary to use a volume of reagent several times the volume of the conduit to flush and clear the conduit.

[0004]

[0004] Specifically, if a conduit or flow cell with volume V and filled with some reagent a is to be completely filled with another reagent b, the required amount of reagent b must be at least rV, where r > 1 is defined as the displacement rate. r is a number related to many variables, such as the conduit geometry, the viscosity and density ratios of reagents a and b, the flow rate, etc. Both experiments and numerical simulations have shown that for a section of straight conduit with a circular cross section, r is typically between 4 and 5, and for a channel whose height is much smaller than its length and width (e.g., 100 times its height), r is between 1.5 and 2. These two basic geometries are very common in fluid systems for medical testing equipment. For example, in a genetic sequencer, the DNA fragment to be tested is usually immobilized in a flow cell. To minimize the internal volume of the flow cell as much as possible to reduce the amount of reagent required, while at the same time ensuring that the DNA fragments being tested are spread as far as possible across the test plane, the typical height dimension of a flow cell channel is generally only 50–100 microns, much smaller than the length and width (measured in millimeters or centimeters) that make up the test plane. Additionally, flow cells are typically fluidly connected to reagent reservoirs, waste reservoirs, pump / valve components, etc., upstream and downstream of the flow cell using standard, easily fabricated round conduits. Assume a flow cell with volume V1, whose upstream section is smoothly connected to a portion of a round conduit with internal volume V2. Both the flow cell and the round conduit are completely filled with reagent a. For ease of calculation, the value of r for the flow cell is fixed at 2, and the value of r for the round conduit is fixed at 5. In this case, when reagent b is injected into the inlet end of the round conduit, 5V2 of reagent b is required to completely replace reagent a in the round conduit, and 2V1 of reagent b is required to completely replace reagent a in the flow cell. Considering that some reagent b enters the flow cell during the replacement process of the round tubing upstream, the final volume of reagent b used is generally between 2V1 and 2V1 + 5V2.Due to the characteristics of Poiseuille flow, it can be seen that the amount of reagent used not only depends on the internal volume V1 of the inspection area, but is also highly related to the internal volume V2 of the pipeline in the upstream part of the inspection area. Especially in some fluid systems where the inspection area is smaller than the volume of the pipeline in the upstream part (i.e., V1 < V2), a large amount of reagent is required to ensure the reagent concentration and reaction efficiency in the inspection area. To reduce the amount of reagent used, an obvious solution is to reduce the volume or relative volume of the pipeline in the upstream part (i.e., reduce V2 or V2 / V1), which can be achieved by reducing the cross-sectional area or length of the pipeline. However, reducing the cross-sectional area of the pipeline inevitably leads to an increase in the overall pressure loss, thereby increasing the load on the fluid system. There is a lower limit to the length of the pipeline due to the constraints of the physical space inside the device. In short, it is impossible to reduce V2 or V2 / V1 to zero.

[0005]

[0005] In addition, another technical solution that can effectively reduce the amount of reagent used is reagent recovery. How to avoid cross-contamination caused by other reagents being recovered into the flow cell during reagent recovery has become an issue that needs to be solved.

Summary of the Invention

[0006] (Summary)

[0006] This application provides a flow path system, a gene sequencer, and a reagent recovery method for avoiding cross-contamination caused by the reagent of the previous reaction being recovered into the flow cell.

[0007] In a first aspect, the present application provides a flow path system including at least two reagent storage containers, a flow cell, a diversion module, and a fluid power unit, wherein the at least two reagent storage containers are configured to store at least two different reagents, respectively. The flow cell is configured to accommodate a sample, and the flow cell is connected to the at least two reagent storage containers. The diversion module includes a diversion structure and at least two diversion channels, wherein the diversion structure has a focusing port in fluid communication with the flow cell and at least two diversion ports corresponding to the at least two diversion channels. A fluid power unit is connected to the diversion module, the fluid power unit selectively communicating with one of the at least two diversion channels, the fluid power unit configured to drive reagents in a forward flow from the reagent storage containers toward the diversion module, and the fluid power unit is further configured to drive reagents in a reverse flow from the diversion module toward the reagent storage containers.

[0008] In some embodiments, the at least two branch channels and the at least two reagent reservoirs are provided in one-to-one correspondence.

[0009]

[0009] In some embodiments, the at least two branch channels include a first branch channel and a second branch channel, and the branch structure includes a three-way tube, which includes a focusing port fluidly connected to the flow cell, a first branch port communicating with the first branch channel, and a second branch port communicating with the second branch channel.

[0010] In some embodiments, the flow diversion structure further includes an on-off control valve, the on-off control valve being provided in the first flow diversion channel and / or the second flow diversion channel.

[0011]

[0011] In some embodiments, the at least two diversion channels include a first diversion channel and a second diversion channel, and the diversion structure includes a first reverse valve, the first reverse valve having a first port, a second port and a third port, the first port forming a focusing port, the second port forming a first diversion port communicating with the first diversion channel, and the third port forming a second diversion port communicating with the second diversion channel, and the first reverse valve operates to control communication of the first port with the second port or the third port.

[0012]

[0012] In some embodiments, the fluid power unit includes an injection pump, the injection pump including a first power port and a second power port, the first power port fluidly connected to the first branch channel and the second power port fluidly connected to the second branch channel.

[0013] In some embodiments, the flow path system further includes a waste cell, and the injection pump further includes a third power port, the third power port in communication with the waste cell.

[0014]

[0014] In some embodiments, the fluid power unit includes an injection pump and a second reverse valve, the injection pump including a first power port, the second reverse valve having a first port, a second port and a third port, the first port and the second port being connected to the first branch channel and the second branch channel, respectively, the third port being connected to the first power port of the injection pump, and the second reverse valve operating to control communication of the third port with the first port or the second port.

[0015] In some embodiments, the flow path system further includes a waste cell, and the infusion pump further includes a second power port, the second power port of the infusion pump communicating with the waste cell.

[0016]

[0016] In some embodiments, the fluid power unit includes a first peristaltic pump and a second peristaltic pump, the flow path system further includes a waste cell, the first diversion channel and the second diversion channel both communicate with the waste cell, the first peristaltic pump is provided in the first diversion channel, and the second peristaltic pump is provided in the second diversion channel.

[0017]

[0017] In some embodiments, the flow path system further includes a reagent selection component, which includes a common hole and at least two branch holes, the at least two branch holes correspondingly connected to at least two reagent storage containers, the common hole connected to the flow cell, and the common hole selectively communicating with one of the at least two branch holes.

[0018]

[0018] In some embodiments, the fluid power unit includes an injection pump, the flow path system further includes a waste cell and a reagent selection component, both the first branch channel and the second branch channel are in communication with the waste cell, the injection pump includes a power port, the reagent selection component includes a common hole and a plurality of branch holes, the common hole selectively communicates with one of the plurality of branch holes, the plurality of branch holes include at least two reagent branch holes correspondingly communicating with at least two reagent storage containers, and a flow cell branch hole in communication with the flow cell, and the power port of the injection pump is connected to the common hole.

[0019]

[0019] In some embodiments, the flow path system further includes a buffer storage container for storing a buffer solution, the buffer storage container being connected to the flow cell, and the fluid power unit being configured to drive the buffer solution in a forward flow direction from the buffer storage container toward the diversion module.

[0020] In some embodiments, the fluid power unit is configured to drive the reagent from the diversion module in a reverse direction toward the reagent reservoir and back into a line connected to the outlet end of the reagent reservoir.

[0021]

[0021] In a second aspect, the present application provides a gene sequencer including a sequencing slide and the above-mentioned flow channel system, wherein the flow cell is disposed on the sequencing slide.

[0022]

[0022] In a third aspect, the present application provides a reagent recovery method based on the above-mentioned flow path system, wherein the at least two different reagents include a first reagent and a second reagent, the at least two branch channels include a first branch channel and a second branch channel, and the reagent recovery method includes the following steps:

[0023]

[0023] A step of controlling a fluid power unit to drive a first reagent in communication with the first branch channel through the flow cell and the branch structure and into the first branch channel of the at least two branch channels, so that the first reagent undergoes a first reaction with the sample in the flow cell.

[0024]

[0024] Steps of controlling the operation of the fluid power unit to drive a second reagent through the flow cell and the diversion structure, causing the second reagent to undergo a second reaction with the sample in the flow cell, and controlling the fluid power unit to drive the second reagent to flow back toward the reagent storage container after the second reaction.

[0025]

[0025] In some embodiments, the reagent recovery method further includes a step of performing washing after the first reaction by controlling the operation of the fluid power unit to drive a buffer solution through the flow cell and the diversion structure and into the first diversion channel.

[0026]

[0026] In some embodiments, the step of controlling the operation of the fluid power unit to drive a second reagent through the flow cell and the diversion structure, causing the second reagent to undergo a second reaction with the sample in the flow cell, and controlling the fluid power unit to drive the second reagent to flow back toward the reagent storage container after the second reaction includes controlling the fluid power unit to drive the second reagent to communicate with the second diversion channel and through the flow cell and the diversion structure into a second diversion channel of the at least two diversion channels, and controlling the fluid power unit to drive the second reagent to communicate with the second diversion channel and flow back toward the reagent storage container after the second reaction.

[0027]

[0027] In some embodiments, the step of controlling the operation of the fluid power unit to drive the second reagent through the flow cell and the diversion structure, causing the second reagent to undergo a second reaction with the sample in the flow cell, and controlling the fluid power unit to drive the second reagent to flow back toward the reagent storage container after the second reaction includes controlling the fluid power unit to drive the second reagent to communicate with the first diversion channel, through the flow cell and the diversion structure, and into the first diversion channel, and controlling the fluid power unit to drive the second reagent to communicate with the second diversion channel and flow back toward the reagent storage container after the second reaction.

[0028]

[0028] In some embodiments, the reagent recovery method further includes a step of, after the first reaction, causing the recovered first reagent to flow back through a conduit connected to the outlet end of a reagent storage container that stores the first reagent by controlling a fluid power unit to communicate with the first diversion channel and drive the first reagent to flow back toward a reagent storage container.

[0029]

[0029] In some embodiments, the step of controlling the fluid power unit to drive the second reagent to flow backward toward the reagent storage container includes a step of controlling the fluid power unit to drive the second reagent to flow backward toward the reagent storage container, thereby causing the recovered second reagent to flow backward through a conduit connected to the outlet end of the reagent storage container.

[0030]

[0030] Based on various aspects of the present application, a diversion module is provided in the flow path system, and the diversion module includes a diversion structure and at least two diversion channels, so that reagents that need to be recovered can enter a diversion channel different from the reagents of the previous reaction, thereby avoiding cross-contamination caused by reagents from the previous reaction being recovered in the flow cell.

[0031]

[0031] Other features and advantages of the present application will become apparent from the following detailed description of illustrative embodiments thereof, taken in conjunction with the accompanying drawings.

[0032]

[0032] The accompanying drawings described herein are intended to provide further understanding of the present application and to constitute a part of the present application. The outlined embodiments and the description thereof are used to explain the present application and are not to be construed as unnecessary limitations to the present application. The accompanying drawings are as follows: [Brief explanation of the drawings]

[0033] [Figure 1] 1 is a schematic diagram of the structure of a flow channel system in the prior art when a first reagent flows in the forward direction. [Figure 2] FIG. 1 is a schematic diagram of the structure of a flow path system in the prior art when the first reagent is withdrawn in the reverse direction. [Figure 3] 1 is a schematic diagram of the structure of a channel system according to some embodiments of the present application. [Figure 4] 4 is a flowchart of a reagent recovery method based on one embodiment of the flow path system shown in FIG. 3. [Figure 5]FIG. 1 is a step diagram of a reagent recovery method according to some embodiments of the present application. [Figure 6] FIG. 10 is a step diagram of a reagent recovery method according to some other embodiments of the present application. [Figure 7] 1 is a flowchart of a reagent recovery method according to some embodiments of the present application. [Figure 8] 1 is a schematic diagram of the structure of a flow path system according to a first embodiment of the present application. [Figure 9] 9 is a diagram showing changes in the concentration of a reagent in a reagent storage container with the number of cycles when the flow path system shown in FIG. 8 is used for collecting a reagent. [Figure 10] FIG. 4 is a schematic diagram of the structure of a flow path system according to a second embodiment of the present application. [Figure 11] FIG. 10 is a schematic diagram of the structure of a flow path system according to a third embodiment of the present application. [Figure 12] FIG. 10 is a schematic diagram of the structure of a flow path system according to a fourth embodiment of the present application. [Figure 13] FIG. 10 is a schematic diagram of the structure of a flow path system according to a fifth embodiment of the present application. [Figure 14] FIG. 10 is a schematic diagram of the structure of a flow path system according to a sixth embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0034] Detailed Description of the Embodiments

[0047] Hereinafter, the technical solutions in the embodiments of the present application will be clearly and completely described with reference to the accompanying drawings. It is clear that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present application, its applications or uses. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the protection scope of the present application.

[0035]

[0048] Unless otherwise specified, the relative arrangements of components and steps, formulas, and numerical values ​​described in these embodiments do not limit the scope of the present application. At the same time, it should be understood that for ease of explanation, the dimensions of various parts shown in the drawings are not drawn to scale. Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but, where appropriate, the techniques, methods, and equipment should be considered part of the permitted specification. In all examples shown and discussed herein, any specific values ​​should be construed as merely illustrative, not limiting. Thus, other examples of exemplary embodiments may have different values. It should be noted that in the following drawings, like numbers and letters indicate like items, and therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0036]

[0049] For ease of description, spatially relative terms such as "top," "above," "on top of," and "upper" may be used herein to describe the spatial relationship between a device or feature shown in the figures and other devices or features. It should be understood that spatially relative terms are intended to encompass various orientations of the device during use or operation in addition to the orientation shown in the figures. For example, if a device in the figures were inverted, a device described as being "above" or "on" another device or structure would be positioned "below" or "below" the other device or structure. Thus, the exemplary term "above" can encompass both an orientation of "above" and "below." Devices may be positioned in other different ways, and the spatially relative descriptions used herein will be explained accordingly.

[0037]

[0050] As shown in FIGS. 1 and 2, a flow path system in the related art includes a flow cell C1, a first conduit L1, and a second conduit L2. The first conduit L1 is connected to a first end of the flow cell C1, and the second conduit L2 is connected to a second end of the flow cell C1. Arrows FD indicate the flow direction. In the flow path system shown in FIGS. 1 and 2, in each reaction cycle, the sample first undergoes a first reaction with a first reagent, then a second reaction with a second reagent, and the above reaction cycle is then repeated multiple times. Then, when two reaction cycles occur, the second reagent in the first reaction cycle reacts first, and the first reagent in the second reaction cycle reacts afterwards. FIG. 1 shows a schematic diagram of a first reagent R1 flowing in the forward direction from the first conduit L1 to the second conduit L2 in a reaction cycle. As shown in Fig. 1, when the first reagent R1 flows forward from the first conduit L1 to the second conduit L2, the buffer solution S and the second reagent R2 from the previous reaction cycle still remain in the second conduit L2. Fig. 2 shows a schematic diagram of the first reagent R1 flowing backward from the second conduit L2 to the first conduit L1. That is, Fig. 2 shows a schematic diagram of the recovery of the first reagent R1.

[0038]

[0051] Due to the characteristics of Poiseuille flow, i.e., the parabolic distribution of flow velocity in a closed conduit or channel, the interface between reagents is not a straight line but a more complex curve. As can be seen from Figure 1, when a first reagent R1 flows forward from left to right into flow cell C1, second conduit L2 contains buffer solution S, which has been displaced by the first reagent R1, and second reagent R2, which was previously displaced. In this case, the interface between the first reagent R1 and buffer solution S and the interface between buffer solution S and second reagent R2 are both parabolic, and buffer solution S acts as a barrier between the first reagent R1 and second reagent R2. Therefore, when a portion of the first reagent R1 is collected in the reverse direction from right to left (see Figure 2), a small amount of second reagent R2 may flow back along the middle of the flow cell into flow cell C1 because the flow velocity is fastest in the middle of the flow cell. This can have adverse effects in some reaction systems that must be performed in a certain order. For example, gene sequencing typically requires a cyclical "synthesis-test-removal" process for each base in a single-stranded DNA fragment. During the synthesis phase, a free base bearing a fluorophore enters the flow cell using the synthesis reagent as a medium and complements the single-stranded DNA to be tested, immobilized on the surface of the flow cell, under the action of a polymerase. In the subsequent inspection phase, an optical system develops the fluorophore to identify the base in the current cycle. Finally, a removal reagent enters the flow cell to remove the fluorophore, completing the current cycle. In Figures 1 and 2, assume that the first reagent R1 is the synthesis reagent and the second reagent R2 is the removal reagent from the previous cycle. When the first reagent R1 enters flow cell C1 (Figure 1), a new cycle of the synthesis reaction begins. At this time, in the "synthesis-test-removal" sequence, optical development should be performed next. However, due to reagent recovery, some of the removal reagent flows back into the flow cell (Figure 2), thereby separating some of the bound fluorophore from the base. This unexpected removal reaction prior to optical color development desynchronizes the overall flow cell sequencing process, resulting in sequencing errors.Therefore, how to avoid cross-contamination caused by the reagents from the previous reaction flowing back into the flow cell during reagent recovery is an urgent technical issue that needs to be resolved.

[0039]

[0052] In addition, all existing recovery solutions collect recovered reagents directly into a reagent storage container. Because the reagents inevitably mix with the liquid previously occupying the flow cell and its first line while entering the flow cell in the forward direction, their concentration inevitably decreases after being recovered in the reverse direction. As a result, the reagents are repeatedly diluted during multiple recovery and reuse cycles, making it impossible to guarantee the effective concentration of the reagents used in the reaction in the flow cell. Furthermore, these recovered reagents further dilute the unused reagents in the containers when they enter the storage cell or container. For reaction systems in which the concentration is positively correlated with the reaction efficiency, the diluted reagents can significantly reduce the reaction efficiency in the flow cell. Furthermore, the reduction in reagent concentration is positively correlated with the number of recovery cycles. For example, if the reagent concentration decreases by 10% with each recovery, the concentration will decrease by 34% after four cycles. Therefore, the higher the recovery rate, the lower the overall reaction efficiency in the flow cell. Therefore, how to guarantee the concentration of reagents involved in biochemical reactions is also a problem that needs to be solved.

[0040]

[0053] In order to avoid cross-contamination caused by reagents from the previous reaction flowing back into the flow cell, the present application provides a technical solution of arranging a diversion channel at the second end of the flow cell C1 (the downstream end when the reagents flow in the forward direction) to divert the reagents that need to be recovered and the reagents from the previous reaction, thereby avoiding cross-contamination.

[0041]

[0054] Referring to FIG. 3 , a flow path system according to one embodiment of the present application includes at least two reagent reservoirs (not shown), a flow cell C1, a diversion module, and a fluid power unit (not shown), where the at least two reagent reservoirs are configured to store at least two different reagents, respectively. The flow cell C1 is configured to accommodate a sample, and the flow cell C1 is connected to the at least two reagent reservoirs. The diversion module includes a diversion structure C2 and at least two diversion channels. The diversion structure C2 has a focusing port fluidly communicating with the flow cell C1 and at least two diversion ports corresponding to the at least two diversion channels. The fluid power unit is connected to the diversion module. The fluid power unit selectively communicates with one of the at least two diversion channels, and the fluid power unit is configured to drive reagents in a forward flow from the reagent reservoirs toward the diversion module. The fluid power unit is further configured to drive reagents in a reverse flow from the diversion module toward the reagent reservoirs.

[0042]

[0055] 3, the flow path system includes at least two reagent reservoirs (not shown), a flow cell C1, a first conduit L1 connected to a first end of the flow cell C1, a second conduit L2 connected to a second end of the flow cell C1, a shunt structure C2, and at least two shunt channels. Specifically, FIG. 3 shows that the at least two shunt channels include a first shunt channel L3 and a second shunt channel L4.

[0043]

[0056] It should be noted that the first conduit L1 is configured to be fluidly connected to a reagent reservoir, and a component for reagent selection, such as a switching valve, may be provided between the first conduit L1 and the reagent reservoir. Similarly, the first and second diversion channels L3 and L4 may be further fluidly connected to other functional modules, such as valves for flow path control and fluid power units for driving fluids. The diversion structure C2 may be a simple three-way component (such as a T-shaped three-way component or a Y-shaped three-way component) or a control component such as a three-way solenoid valve, or a combination thereof. In addition, depending on the needs of actual applications, the diversion structure C2 may be divided into more than two branches, and each branch may be divided into more branches via one or more diversion modules. All of these downstream-extending bypass designs are within the scope of protection of the present application.

[0044]

[0057] Based on the flow path system design in FIG. 3, a set of reagent recovery logic can be established to avoid cross-contamination in flow cell C1, as shown in FIG. 4. For ease of understanding, only two reaction steps, namely, the first reaction and the second reaction, are involved here. Note that in FIG. 4, only the reagents used in the second reaction are recovered for simplicity of discussion, but this does not mean that the reagents used in the first reaction cannot be recovered. Referring to FIG. 4, the overall recovery logic mainly includes the following steps:

[0045]

[0058] S1: The first conduit L1 is fluidly connected to a reagent storage container containing the first reagent 101 (in Figure 4, the reagent selection component and the reagent storage container are not labeled), and the reagent selection component located upstream of the first conduit L1 is switched so that the fluid power unit is connected to the first diversion channel L3, and then the first reagent 101 is driven by the fluid power unit to sequentially replace the buffer solution 102 in the first conduit L1, the flow cell C1, the second conduit L2 and the diversion structure C2, and finally flows out along the first diversion channel L3, and in this case, the parabolic interface between the first reagent 101 and the buffer solution 102 is located in the first diversion channel L3.

[0046]

[0059] S2: At the end of S1, the first reagent 101 in the flow cell C1 immediately undergoes a first reaction with the sample immobilized on the flow cell C1.

[0047]

[0060] S3: After the first reaction is completed, the reagent selection component is switched so that the first conduit L1 is fluidly connected to a buffer storage container containing buffer 102, and the buffer 102 is driven by the fluid power unit to sequentially wash the first reagent 101 in the first conduit L1, flow cell C1, second conduit L2, and diversion structure C2, and finally flows out along the first diversion channel L3, in which case the interface between the buffer 102 and the first reagent 101 is located in the first diversion channel L3, ensuring that the first reagent 101 completely leaves the diversion structure C2.

[0048]

[0061] S4: The first conduit L1 is fluidly connected to a reagent storage container containing the second reagent 103, and the reagent selection component is switched so that the fluid power unit is connected to the second diversion channel L4, and the second reagent 103 is then driven by the fluid power unit to sequentially replace the buffer solution 102 in the first conduit L1, flow cell C1, second conduit L2 and diversion structure C2, and finally flows out along the second diversion channel L4, in which case the parabolic interface between the second reagent 103 and the buffer solution 102 is located in the second diversion channel L4, and the second reagent 103 in the diversion structure C2 does not mix with the first reagent 101 in the first diversion channel L3.

[0049]

[0062] S5: At the end of S4, the second reagent 103 in the flow cell C1 immediately undergoes a second reaction with the sample immobilized on the flow cell C1.

[0050]

[0063] S6: After the second reaction is completed, the fluid power unit drives the second reagent 103 in the reverse direction to sequentially leave the second diversion channel L4, the diversion structure C2, the second conduit L2 and the flow cell C1 to realize the recovery of the second reagent 103.

[0051]

[0064] S1 to S6 illustrate the recovery policy of a single reagent (i.e., the second reagent 103) in the two reaction systems. The first reagent 101 and the second reagent 103 are delivered to the first branch channel L3 and the second branch channel L4, respectively, and a buffer solution is provided between the first reagent 101 and the second reagent 103. When the second reagent 103 is recovered, the first reagent 101 does not flow back through the flow cell, thereby avoiding the recurrence of the first reaction.

[0052]

[0065] 4 illustrates the recovery process of the second reagent 103. However, in another possible reagent recovery method, the first reagent 101 may be recovered after the first reaction is completed. For example, after the first reaction, the fluid power unit reversely drives the first reagent 101 to sequentially leave the first diversion channel L3, the diversion structure C2, the second conduit L2, and the flow cell C1 to recover the first reagent 101. Regarding the cycle reaction, the second reagent 103 from the previous cycle reaction flows into the second diversion channel L4. Therefore, when the first reagent 101 is recovered, the second reagent 103 does not flow back into the flow cell C1, thereby avoiding cross-contamination. In summary, the flow path system of the present application allows the first reagent and the second reagent to enter different diversion channels by the diversion module. As a result, when one reagent is recovered, the other reagent does not flow back into the flow cell. That is, the flow path system of the present application can recover not only the second reagent but also both the first reagent and the second reagent.

[0053]

[0066] In the above embodiment, to allow the first reagent 101 and the second reagent 103 to enter different diversion channels, the fluid power unit must be able to select between the first diversion channel and the second diversion channel, thereby ensuring that the liquid in one channel remains stationary when the liquid in the other channel flows. That is, the fluid power unit is configured to selectively communicate with one of at least two diversion channels. Furthermore, in the above embodiment, the reagent must flow in a forward direction into the flow cell to carry out a reaction. If the reagent needs to be recovered, the reagent must also flow in a reverse direction from the diversion module. The above-mentioned bidirectional flow of the reagent is achieved by the fluid power unit. The fluid power unit is configured to drive the reagent in a forward flow from the reagent reservoir toward the diversion module. The fluid power unit is further configured to drive the reagent in a reverse flow from the diversion module toward the reagent reservoir. Specifically, the fluid power unit may include a power device capable of both forward and reverse driving. The fluid power unit may include a forward power device capable of driving in a forward direction and a reverse power device capable of driving in a reverse direction.

[0054]

[0067] In summary, in the technical solution of the embodiment of the present application, by arranging a diversion module including a diversion structure and at least two diversion channels, the reagents that need to be recovered can enter a diversion channel different from the reagents from the previous reaction, thereby avoiding cross-contamination caused by the reagents used in the previous reaction being recovered in the flow cell.

[0055]

[0068] 5, an embodiment of the present application further provides a reagent recovery method, which includes the following steps:

[0056]

[0069] S101: Controlling the fluid power unit to drive a first reagent 101 to communicate with a first diversion channel L3 and pass through the flow cell C1 and the diversion structure C2 into the first diversion channel L3 of the at least two diversion channels, so that the first reagent 101 undergoes a first reaction with the sample in the flow cell C1.

[0057]

[0070] S102: Control the operation of the fluid power unit to drive the second reagent 103 through the flow cell C1 and the diversion structure C2, and control the fluid power unit to drive the second reagent 103 to undergo a second reaction with the sample in the flow cell C1 and, after the second reaction, to flow back toward the reagent storage container.

[0058]

[0071] In some embodiments, the flow path system further includes a buffer reservoir for storing a buffer solution, the buffer reservoir connected to the flow cell, and the fluid power unit configured to drive the buffer solution in a forward flow direction from the buffer reservoir toward the shunt module.

[0059]

[0072] In some embodiments, the reagent recovery method further includes controlling operation of the fluid power unit to drive a buffer solution through the flow cell and the shunting structure into a first shunt channel after the first reaction to perform a wash, controlling the fluid power unit to drive a second reagent, after the wash, into communication with the second shunt channel through the flow cell and the shunting structure into a second of the at least two shunt channels, and controlling the fluid power unit to drive the second reagent, after the second reaction, into communication with the second shunt channel and backflow toward the reagent reservoir. That is, in this embodiment, a buffer wash process is provided between the first reaction and the second reaction, allowing the first reagent and the second reagent to enter two different shunt channels, respectively.

[0060]

[0073] In other embodiments, a buffer wash process may not be performed between the first and second reactions. The steps of controlling the operation of the fluid power unit to drive a second reagent through the flow cell and the shunting structure, causing the second reagent to undergo a second reaction with the sample in the flow cell, and controlling the fluid power unit to drive the second reagent to flow back toward the reagent reservoir after the second reaction include controlling the fluid power unit to drive the second reagent to communicate with the first shunt channel, through the flow cell and the shunting structure, and into the first shunt channel, and controlling the fluid power unit to drive the second reagent to communicate with the second shunt channel and flow back toward the reagent reservoir after the second reaction. That is, after the first reaction, the second reagent directly replaces the first reagent in the flow cell and eventually flows out along the first shunt channel. In this case, the interface between the first and second reagents is located in the first shunt channel. The collection of the second reagent is then switched to the second diversion channel.

[0061]

[0074] In some embodiments, the at least two diversion channels and the at least two reagent reservoirs are provided in one-to-one correspondence, i.e., each reagent enters a different diversion channel, thereby preventing other reagents from flowing back into the flow cell during collection.

[0062]

[0075] In another embodiment, to reduce the size and simplify the structure of the fluidic system, the diversion module of the fluidic system includes two diversion channels. In a cyclic reaction involving two reagents, one reagent is controlled to flow into the first diversion channel, and the other reagent is controlled to flow into the second diversion channel. In other words, the reagents can be recovered according to the recovery policy shown in FIG. 6. In a multi-cycle reaction involving multiple reagents, the reagents used in each step must enter a diversion channel different from the reagents used in the previous reaction to prevent the reagents used in the previous reaction from flowing back into the flow cell and causing an inappropriate reaction.

[0063]

[0076] In one possible situation, when one reagent is collected, not only may reagents from a previous reaction flow back into the flow cell, but also reagents from two or more previous reactions may flow back into the flow cell. This can be resolved by increasing the volume of buffer between the reagents, reducing the collection rate, or adding more reagent channels after the diversion module. For example, the at least two diversion channels and at least two reagent reservoirs described in the above embodiment are provided in one-to-one correspondence, so that each reagent enters the corresponding diversion channel, thereby avoiding cross-contamination.

[0064]

[0077] The inventors of the present application have also conducted in-depth research into the problem of how to ensure the concentration of reagents involved in biochemical reactions during reagent recovery. In some embodiments, the fluid power unit is configured to drive the reagent from the diversion module to flow in a reverse direction toward the reagent storage container and return to the conduit connected to the outlet end of the reagent storage container. For example, in the case of recovering a second reagent, the step of controlling the fluid power unit to drive the second reagent to flow reversely toward the reagent storage container includes controlling the fluid power unit to drive the second reagent to flow reversely toward the reagent storage container, thereby causing the recovered second reagent to flow reversely through the conduit connected to the outlet end of the reagent storage container. In other words, the recovered second reagent only flows reversely through the conduit connected to the outlet end of the reagent storage container and does not return to the reagent storage container. This ensures that the reagent in the reagent storage container is not diluted.

[0065]

[0078] Specifically, the recovery rate can be adjusted to prevent recovered reagent from returning to the reagent reservoir, for example, by controlling the volume of reagent recovered.

[0066]

[0079] Of course, if necessary, the recovered reagent can be returned partially or completely to the reagent reservoir, as long as the diluted reagent in the reagent reservoir meets the requirements for reuse.

[0067]

[0080] 7, the flow path system includes a first storage container 111, a second storage container 112, a third storage container 113, a reagent selection component C3, a first conduit L1, a flow cell C1, and a second conduit L2. The first storage container 111 is configured to store a first reagent 101, the second storage container 112 is configured to store a buffer solution 102, and the third storage container 113 is configured to store a second reagent 103. FIG. 7A shows the recovery process of the current cycle, and FIG. 7B shows the second reaction of the next cycle. As shown in FIG. 7A, after recovery is completed, a certain volume of the second reagent 103, including a portion 1031 diluted due to direct contact with the buffer solution 102 and a substantially undiluted portion 1032, is recovered upstream of the flow cell C3. Because the diluted portion 1031 is downstream of the undiluted portion 1032, it is certain that when the second reagent 103 is used in the next cycle, the diluted portion 1031 will first participate in reagent displacement in the first line L1 and flow cell C1, as shown in Figure 7B. At high flow rates, the diluted portion 1031 will only initiate a weak second reaction (almost negligible) as it passes through the flow cell. As the second reagent 103 continues to flow downstream, the nearly undiluted portion 1032 will enter the flow cell, where the flow will stop, and this portion will fully react with the sample in the flow cell.

[0068]

[0081] The technical solution of the present application realizes efficient reagent recovery and reuse through the design of the flow path system and recovery logic, thereby greatly reducing the amount of reagent consumed in closed pipelines and channels, thereby significantly reducing the cost of reagent consumables in medical testing equipment. Here, the present application has the following two main advantages:

[0069]

[0082] 1) By installing a diversion module, the reagent that needs to be collected is diverted from the previous reagent, thereby solving the problem of cross-contamination in the flow cell after reagent collection. This prevents the orderly reaction system of a complex cycle in precision instruments such as genetic sequencers from being disrupted by reagent collection, ensuring the quality of biochemical reactions. When the volume of the flow cell is small compared to the volume of the upstream and downstream piping, cross-contamination is likely to occur due to reagent collection. This solution makes it possible to achieve a high recovery rate even with a small flow cell.

[0070]

[0083] 2) The recovery of reagents does not result in a significant reduction in the overall concentration of the reagents in the storage containers. The low-concentration portion of the recovered reagents is not involved in the biochemical reaction, but is mainly used to replace other liquids in the flow cell and its upstream common line. The biochemical reaction is still carried out at a high reagent concentration, ensuring the efficiency of the reaction.

[0071]

[0084] Referring to FIG. 8 , in some embodiments, the at least two diversion channels include a first diversion channel 206 and a second diversion channel 207, and the diversion structure includes a three-way tube 202, which includes a focusing port fluidly connected to the flow cell, a first diversion port connected to the first diversion channel 206, and a second diversion port connected to the second diversion channel 207.

[0072]

[0085] The flow channel system of the gene sequencer according to the first embodiment shown in Fig. 8 is taken as an example for detailed description. As shown in Fig. 8, the flow channel system includes a storage container 208, a reagent selection component 203, a first conduit 204, a sequencing slide 201, a second conduit 205, a three-way tube 202, a first diversion channel 206, a second diversion channel 207, an injection pump 209, a third conduit 210, and a waste cell 211.

[0073]

[0086] The storage containers 208 include a first storage container for storing a synthesis reagent 221, a second storage container for storing a scan reagent 222, a third storage container for storing a removal reagent 223, and a fourth storage container for storing a buffer solution 224. The sequencing slide 201 has a flow cell.

[0074]

[0087] The reagent selection component 203 is configured to selectively fluidly connect the flow cell to one of the reservoirs 208, thereby allowing a corresponding reagent to enter the flow cell. The reagent selection component 203 includes a common hole and at least two branch holes, the at least two branch holes correspondingly connected to the at least two reagent reservoirs, the common hole connected to the flow cell via the first conduit 204, and the common hole selectively connected to one of the at least two branch holes. Specifically, the reagent selection component 203 is configured as a reagent selector valve.

[0075]

[0088] The three-way tube 202 forms a diversion structure. The three-way tube 202 includes a focusing port in fluid communication with the flow cell, a first diversion port in communication with a first diversion channel 206, and a second diversion port in communication with a second diversion channel 207. Specifically, the three-way tube 202 is a T-shaped three-way tube. In other embodiments, it may be a Y-shaped three-way component.

[0076]

[0089] In other embodiments, the flow distribution structure may include a multi-way tube, such as a four-way tube, to provide more flow distribution channels.

[0077]

[0090] Infusion pump 209 forms a fluid power unit. Infusion pump 209 has three power ports: a first power port fluidly connected to first diversion channel 206, a second power port fluidly connected to second diversion channel 207, and a third power port fluidly connected to waste cell 211 via third conduit 210. Infusion pump 209 can selectively supply a driving force to one of the three power ports. Infusion pump 209 can supply a forward driving force for the forward flow of reagents and a reverse driving force for the reverse flow of reagents. Of course, in other embodiments, the fluid power unit can include two independently arranged infusion pumps, one of which is configured to supply a forward driving force to a reagent and the other of which is configured to supply a reverse driving force to a reagent.

[0078]

[0091] The operation process of the fluidic system according to the first embodiment shown in FIG. 8 is described in detail below. In this figure, solid arrows indicate the flow direction of reagents in the forward flow direction, and dotted arrows indicate the flow direction of reagents in the reverse recovery direction. The DNA fragments to be tested are immobilized on the surface of the flow cell of the sequencing slide, and the overall sequencing process is a cyclic "synthesize-test-remove" system, as described above. For simplicity, each step involves only one reagent, and a buffer solution is used as a barrier between the reagents between two steps. Note that the flow cell in this embodiment, with a volume of approximately 4 μL, is a typical small-volume flow cell. By comparison, the volume of first conduit 204 is 4 μL, the total volume of reagent selection component 203 and the conduit between reagent selection component 203 and reservoir 208 is approximately 30 μL, the volume of second conduit 205 is 10 μL, and the volumes of first diversion channel 206 and second diversion channel 207 are both 100 μL or more. Prior to sequencing, each reagent in reservoir 208 is pre-filled into the conduit between the reservoir and reagent selection component 203. Therefore, during the sequencing process, reagent displacement occurs primarily in first conduit 204 and the flow cell of sequencing slide 201.

[0079]

[0092] In this embodiment, the complete reaction cycle includes the following steps: 1) The reagent selection component 203 is switched to be fluidly connected to the first reservoir, and the infusion pump 209 is switched to be fluidly connected to the first shunt channel 206, and 40 μL of synthesis reagent 221 is pumped at a high flow rate (e.g., 2000 μL / min, same below) through the sequencing slide 201. In this step, the synthesis reagent 221 replaces the buffer solution 224 originally present in the first conduit 204 and the flow cell. 2) The synthesis reaction is carried out in the flow cell for a period of time. 3) The injection pump 209 pushes 30 μL of the synthesis reagent 221 in the reverse direction (see the dotted arrow in FIG. 8) along the first diversion channel 206 to the upstream portion, and the diluted portion of the synthesis reagent 221 flows back into the conduit between the reagent selection component 203 and the reservoir 208, but not back into the reservoir 208. 4) The reagent selection component 203 is switched to be fluidically connected to the fourth reservoir, and the injection pump 209 remains fluidically connected to the first diversion channel 206, and 50 μL of buffer solution 224 is pumped through the sequencing slide 201 to replace the remaining synthesis reagent 221 in the first conduit 204 and flow cell. 5) The reagent selection component 203 is switched to be fluidically connected to the second storage container, the injection pump 209 remains fluidically connected to the first diversion channel 206, and 40 μL of scan reagent 222 is pumped to flow through the sequencing slide 201, which is then inspected by an optical system (not shown). 6) The reagent selection component 203 is switched to be fluidly connected to the fourth reservoir, and 50 μL of buffer solution 224 is pumped by the injection pump 209 through the sequencing slide 201 to replace the scan reagent 222 in the first line 204 and flow cell. 7) The reagent selection component 203 is switched to be fluidly connected to the third storage container, and the injection pump 209 is switched to be fluidly connected to the second diversion channel 207, and 40 μL of removal reagent 223 is pumped through the sequencing slide 201. 8) The removal reaction is carried out in the flow cell for a period of time. 9) The reagent selection component 203 is switched to be fluidly connected to the fourth reservoir, and the injection pump 209 remains fluidly connected to the second diversion channel 207, pumping 50 μL of buffer solution 224 through the sequencing slide 201 to replace the removal reagent 223 in the first conduit 204 and flow cell. 10) Infusion pump 209 is switched to be fluidly connected to third line 210 and waste cell 211 to drain the fluid from the infusion pump.

[0080]

[0093] In the above steps, 40 μL of the synthesis reagent 221 is first pumped, and then 30 μL is recovered. Therefore, the recovery rate is calculated as 30 / 40=75%, the actual consumption amount is calculated as 40-30=10 μL, and the replacement rate r for the flow cell volume (4 μL) is calculated as 10 / 4=2.5. If reagent recovery is not performed, the replacement rate is calculated as 40 / 4=10. It can be seen that after the recovery policy of the present application is introduced, the replacement rate is reduced to 1 / 4 of the original rate.

[0081]

[0094] From the perspective of sequencing quality, high reagent recovery does not significantly affect sequencing results. Table 1 compares the sequencing quality indicators for no recovery and 75% recovery. Both are at the same level in terms of total reads and quality value (Q30).

[0082] [Table 1]

[0083]

[0095] In this embodiment, the introduction of the T-shaped three-way tube 202, first diversion channel 206, and second diversion channel 207 into the outlet end of the flow cell successfully solves the problem of cross-contamination in the flow cell caused by backflow of removal reagent 223 due to reagent recovery. By measuring the concentration of the remaining removal reagent in the flow cell after recovery, it was found that without the introduction of the three-way tube 202 and diversion channel, the residual concentration was 0.7%, while the residual concentration after introduction was negligible. Because a very small amount of removal reagent can cause improper reactions and sequencing errors, the technical solution of this application is very important for gene sequencing.

[0084]

[0096] In the embodiment shown in FIG. 8 , the synthesis reagent 221 enters the first diversion channel 206, and the removal reagent 223 enters the second diversion channel 207. Therefore, while the synthesis reagent 221 is being collected, the problem of cross-contamination caused by the removal reagent 223 flowing back into the flow cell can be avoided. Of course, if necessary, the removal reagent 223 can also be collected, thereby avoiding the problem of cross-contamination caused by the synthesis reagent 221 flowing back into the flow cell. Additionally, in the case of multiple cycles involving multiple reagents, in some embodiments, the reagents used in each cycle can be placed in a diversion channel different from the reagents used in the previous reaction. However, when reagents are collected, the following situation may occur: a reagent used in two or more previous reactions may be in the same diversion channel as the reagent to be collected, causing backflow. This can be avoided by increasing the volume of buffer between the reagents. In other embodiments, depending on the type of reagent, it can be determined whether the reagents used in each cycle should be placed in a diversion channel different from the reagents used in the previous reaction. The key question is whether an undesired reaction will occur if a reagent used in a current reaction enters the same diversion channel as a reagent used in a previous reaction. For example, in the embodiment shown in FIG. 8 involving synthesis reagent 221, scan reagent 222, and removal reagent 223, the reaction sequence is synthesis-scan-removal. Because scan reagent 222 flowing back into the flow cell will not cause an undesired reaction, but removal reagent 223 flowing back into the flow cell will, in the above embodiment, both synthesis reagent 221 and scan reagent 222 flow into first diversion channel 206, and removal reagent 223 flows into second diversion channel 207. This arrangement is primarily intended to allow removal reagent 223 to enter a different diversion channel from scan reagent 222.

[0085]

[0097] In this embodiment, the synthesis reagent is recovered after the reaction and is not collected in the storage container 208. When reused in the next cycle, the dilution portion is mainly responsible for reagent replacement, and the concentration of the reagent involved in the reaction in the flow cell is maintained at a high level. This advantage can be demonstrated by the plot of synthesis reagent concentration against the number of cycles in the flow cell shown in Figure 9. From this figure, it can be seen that the synthesis reagent concentration maintains more than 98.7% of the effective relative concentration within 100 cycles, which fully demonstrates the main advantage of the technical solution described herein.

[0086]

[0098] 10 , in some embodiments, the diversion module further includes an on-off control valve, which is provided in the first diversion channel 206 and / or the second diversion channel 207. By providing the on-off control valve in the first diversion channel 206 and / or the second diversion channel 207, a physical barrier can be reinforced, thereby completely isolating a reagent used in a previous reaction in another diversion channel during reagent recovery.

[0087]

[0099] Specifically, the channel system of the gene sequencer according to the second embodiment shown in FIG. 10 is taken as an example for detailed explanation.

[0088]

[0100] A modification made in the second embodiment compared to the first embodiment is that an on-off control valve, specifically a two-position two-way solenoid valve 212, is added to the second branch channel 207. The solenoid valve functions to reinforce a physical barrier, so that the removal reagent remains completely in the second branch channel 207 during the recovery of the synthesis reagent. In the design of the embodiment shown in FIG. 8 , the three-way tube 202, the first branch channel 206, and the second branch channel 207 all form a passage. Therefore, when the synthesis reagent is recovered along the first branch channel 206, the removal reagent in the second branch channel 207 may still partially backflow into the flow cell due to the unequal flow resistance of the first branch channel 206 and the second branch channel 207, air bubbles in the pipeline, etc. This embodiment can solve this problem by introducing the solenoid valve 212. The solenoid valve 212 forms a passage when power is applied and blocks the passage when power is cut off.

[0089]

[0101] In this embodiment, the procedure for collecting the reagent is slightly different from that in the first embodiment, and is specifically as follows. 1) The reagent selection component 203 is switched to be fluidly connected to the first reservoir, the solenoid valve 212 is switched off, and the infusion pump 209 is switched to be fluidly connected to the first shunt channel 206, and 40 μL of synthesis reagent 221 is pumped at a high flow rate (e.g., 2000 μL / min, same below) through the sequencing slide 201. In this step, the synthesis reagent 221 replaces the buffer solution 224 originally present in the first conduit 204 and the flow cell. 2) to 6) are the same as those in the first embodiment. 7) The reagent selection component 203 is switched to be fluidly connected to the third storage container, the solenoid valve 212 is switched on, and the injection pump 209 is switched to be fluidly connected to the second diversion channel 207, and 40 μL of removal reagent 223 is pumped to flow through the sequencing slide 201. 8) to 10) are the same as those in the first embodiment.

[0090]

[0102] In some other embodiments not shown in the drawings, an on-off control valve may be provided in the first diversion channel 206. Alternatively, an on-off control valve may be provided in each of the first and second diversion channels. The on-off control valves may be solenoid valves or other components capable of controlling the opening and closing of a line.

[0091]

[0103] 11 , in some embodiments, the at least two diversion channels include a first diversion channel 206 and a second diversion channel 207. The diversion structure includes a first reverse valve having a first port, a second port, and a third port, where the first port forms a focusing port, the second port forms a first diversion port connected to the first diversion channel 206, and the third port forms a second diversion port connected to the second diversion channel 207, and the first reverse valve operates to control connection of the first port to the second port or the third port.

[0092]

[0104] Specifically, the channel system of the gene sequencer according to the third embodiment shown in FIG. 11 is taken as an example for detailed explanation.

[0093]

[0105] This embodiment is an improved design of the first embodiment. As can be seen from Figure 11, the only change made in this embodiment compared to the first embodiment is replacing the three-way tube with a reverse valve, specifically a two-position three-way solenoid valve 213. The normally open end of the solenoid valve is fluidly connected to the first diversion channel 206, and the normally closed end is fluidly connected to the second diversion channel 207. Similar to the second embodiment, this embodiment has a better physical barrier than the first embodiment.

[0094]

[0106] In this embodiment, the procedure for collecting the reagent is slightly different from that in the first embodiment, and is specifically as follows. 1) The reagent selection component 203 is switched to be fluidly connected to the first reservoir, the solenoid valve 213 remains powered off, and the infusion pump 209 is switched to be fluidly connected to the first shunt channel 206, pumping 40 μL of synthesis reagent 221 at a high flow rate (e.g., 2000 μL / min, same below) through the sequencing slide 201. In this step, the synthesis reagent 221 replaces the buffer solution 224 originally present in the first conduit 204 and the flow cell. 2) to 6) are the same as those in the first embodiment. 7) The reagent selection component 203 is switched to be fluidly connected to the third storage container, the solenoid valve 213 is switched on, and the injection pump 209 is switched to be fluidly connected to the second diversion channel 207, and 40 μL of removal reagent 223 is pumped to flow through the sequencing slide 201. 8) to 10) are the same as those in the first embodiment.

[0095]

[0107] In some embodiments, the fluid power unit includes an infusion pump 209, which includes a first power port and a second power port, the first power port fluidly connected to the first branch channel and the second power port fluidly connected to the second branch channel.

[0096]

[0108] Specifically, with reference to the three embodiments shown in Figures 9, 10 and 11, the injection pump 209 includes a first power port and a second power port, the first power port being fluidly connected to the first branch channel 206 and the second power port being fluidly connected to the second branch channel 207.

[0097]

[0109] Referring to the three embodiments shown in Figures 9, 10 and 11, the flow path system further includes a waste cell 211, and the injection pump 209 further includes a third power port, which is connected to the waste cell 211.

[0098]

[0110] Referring to FIG. 12 , in some embodiments, the fluid power unit includes an infusion pump 214 and a second reverse valve, the infusion pump including a first power port, the second reverse valve having a first port, a second port, and a third port, the first port and the second port connected to the first branch channel and the second branch channel, respectively, the third port connected to the first power port of the infusion pump 214, and the second reverse valve operating to control communication of the third port with either the first port or the second port.

[0099]

[0111] The channel system of the gene sequencer according to the fourth embodiment shown in Figure 12 is taken as an example for detailed description. As can be seen from Figure 12, the modification made in this embodiment compared with the first embodiment is that a reverse valve, specifically a two-position three-way solenoid valve 213, is added to the rear end of the three-way tube 202. The normally open end of the solenoid valve is fluidly connected to the second diversion channel 207, and the normally closed end is fluidly connected to the first diversion channel 206. In addition, the injection pump 214 in this embodiment only has two optional power ports, one end of which is fluidly connected to the solenoid valve 213, and the other end of which is fluidly connected to the third conduit 210 and the waste cell 211.

[0100]

[0112] In this embodiment, the reagent recovery step is slightly different from that in the first embodiment, specifically as follows. 1) The reagent selection component 203 is switched to be fluidly connected to the first reservoir, the solenoid valve 213 is switched on, and 40 μL of synthesis reagent 221 is pumped by the injection pump 214 at a high flow rate (e.g., 2000 μL / min, same below) through the sequencing slide 201. In this step, the synthesis reagent 221 replaces the buffer solution 224 originally present in the first conduit 204 and the flow cell. 2) The synthesis reaction is carried out in the flow cell for a period of time. 3) The injection pump 214 pushes 30 μL of reagent in the reverse direction (see dotted arrow in FIG. 12) upstream along the first diversion channel 206, causing the diluted portion of the synthetic reagent 221 to flow back into the conduit between the reagent selection component 203 and the reagent reservoir 208, but not back into the reagent reservoir 208. 4) The reagent selection component 203 is switched to be fluidly connected to the fourth reservoir, and 50 μL of buffer solution 224 is pumped by the injection pump 214 to flow through the sequencing slide 201 and replace the remaining synthesis reagent 221 in the first line 204 and flow cell. 5) The reagent selection component 203 is switched to be fluidly connected to the second storage container, and 40 μL of scan reagent 222 is pumped by the injection pump 214 to flow through the sequencing slide 201, which is then inspected by an optical system (not shown). 6) The reagent selection component 203 is switched to be fluidly connected to the fourth reservoir, and 50 μL of buffer solution 224 is pumped by the injection pump 214 to flow through the sequencing slide 201 and replace the scan reagent 222 in the first line 204 and flow cell. 7) The reagent selection component 203 is switched to be fluidly connected to the removal reagent 223, the solenoid valve 213 is switched off, and 40 μL of the removal reagent 223 is pumped by the injection pump 214 through the sequencing slide 201 and into the second diversion channel 207. 8) The removal reaction is carried out in the flow cell for a period of time. 9) The reagent selection component 203 is switched to be fluidly connected to the fourth reservoir, and 50 μL of buffer solution 224 is pumped by the injection pump 214 to flow through the sequencing slide 201 and replace the removal reagent 223 in the first line 204 and flow cell. 10) Infusion pump 214 is switched to be fluidly connected to third line 210 and waste cell 211 to drain the fluid from the infusion pump.

[0101]

[0113] In some embodiments, the flow path system further includes a waste cell 211, and the injection pump 214 further includes a second power port, which is connected to the waste cell. As shown in Figure 12, the injection pump 214 includes two power ports, one of which is connected to a reverse valve (two-position three-way solenoid valve 213), and the other power port is connected to the waste cell 211 via a third conduit 210.

[0102]

[0114] 13 , the fluid power unit includes a first peristaltic pump 216 and a second peristaltic pump 217. The flow path system further includes a waste cell 211, and both the first and second diversion channels 206 and 207 are connected to the waste cell 211, with the first peristaltic pump 216 being provided in the first diversion channel 206 and the second peristaltic pump 217 being provided in the second diversion channel 207.

[0103]

[0115] 13 shows a flow path system of a gene sequencer according to a fifth embodiment. As shown in FIG. 13, this embodiment is a modified design of the third embodiment, with the main change being that the infusion pump is replaced with two peristaltic pumps 216 and 217. As can be seen from FIG. 13, the normally open end of the solenoid valve 213 is fluidly connected to the first peristaltic pump 216 via the first shunt channel 206, and the normally closed end is fluidly connected to the second peristaltic pump 217 via the second shunt channel 207.

[0104]

[0116] In this embodiment, the reagent recovery step is slightly different from that in the third embodiment, specifically as follows. 1) The reagent selection component 203 is switched to be fluidly connected to the first reservoir, the solenoid valve 213 remains de-energized, and 40 μL of synthesis reagent 221 is pumped by the injection pump 217 at a high flow rate (e.g., 2000 μL / min, same below) through the sequencing slide 201. In this step, the synthesis reagent 221 replaces the buffer solution 224 originally present in the first conduit 204 and the flow cell. 2) The synthesis reaction is carried out in the flow cell for a period of time. 3) The first peristaltic pump 216 pushes 30 μL of reagent upstream along the first diversion channel 206 in the reverse direction (see dotted arrow in FIG. 14), causing the diluted portion of the composite reagent 221 to flow back into the conduit between the reagent selection component 203 and the reagent reservoir 208, but not back into the reagent reservoir 208. 4) The reagent selection component 203 is switched to be fluidly connected to the fourth reservoir, and 50 μL of buffer solution 224 is pumped by the second peristaltic pump 217 to flow through the sequencing slide 201 and replace the remaining synthesis reagent 221 in the first line 204 and flow cell. 5) The reagent selection component 203 is switched to be fluidly connected to a second storage container, and 40 μL of scan reagent 222 is pumped by a second peristaltic pump 217 to flow through the sequencing slide 201, which is then inspected by an optical system (not shown). 6) The reagent selection component 203 is switched to be fluidly connected to the fourth reservoir, and 50 μL of buffer solution 224 is pumped by the second peristaltic pump 217 to flow through the sequencing slide 201 and replace the scan reagent 222 in the first conduit 204 and flow cell. 7) The reagent selection component 203 is switched to be fluidly connected to the third storage container and the solenoid valve 213 is switched on, in this case pumping 40 μL of removal reagent 223 by the second peristaltic pump 217 through the sequencing slide 201 and into the second diversion channel 207. 8) The removal reaction is carried out in the flow cell for a period of time. 9) The reagent selection component 203 is switched to be fluidly connected to the buffer solution 224, and 50 μL of the buffer solution 224 is pumped by the first peristaltic pump 216 to flow through the sequencing slide 201 and replace the removal reagent 223 in the first conduit 204 and flow cell.

[0105]

[0117] In some embodiments, the fluid power unit includes an infusion pump 214. The fluid path system further includes a waste cell 211 and a reagent selection component 203, wherein the first diversion channel 206 and the second diversion channel 207 are both connected to the waste cell 211, the infusion pump 214 includes a power port, the reagent selection component 203 includes a common hole and a plurality of branch holes, the common hole is selectively connected to one of the plurality of branch holes, the plurality of branch holes include at least two reagent branch holes connected to at least two reagent storage containers corresponding to each other and connected to a flow cell, and a flow cell branch hole connected to a flow cell, and the power port of the infusion pump 214 is connected to the common hole.

[0106]

[0118] FIG. 14 shows a fluidic system of a genetic sequencer according to a sixth embodiment. This fluidic system is a modified embodiment of the third embodiment shown in FIG. 11. Compared to the third embodiment, the main change made in this embodiment is that the infusion pump is placed before and after the reagent selection component, so that the forward reagent flow is positive pressure driven. From FIG. 14, it can be seen that the infusion pump 214 is fluidly connected to the common bore of the reagent selection component 203 via conduit 215, and the common conduit 204 is instead fluidly connected to the branch bore of the reagent selection component 203. In addition, both the diversion channels 206 and 207 of the solenoid valve 213 are fluidly connected to the waste cell 211. In practice, the steps of reagent recovery are basically the same as those in the third embodiment, except that each time liquid is pumped forward, the infusion pump 214 first pumps the reagent from the common port of the reagent selection component 203 to the line 215, then the reagent selection component 203 is switched to be fluidly connected to the first line 204, and finally the infusion pump 214 pushes the reagent into the first line 204. In the case of reagent recovery, the infusion pump 214 first pumps the used reagent from the first line 204 to the line 215, then the reagent selection component 203 is switched to the port corresponding to the reagent, and finally the infusion pump 214 pushes the recovered reagent into the reagent port.

[0107]

[0119] The present application further provides a genetic sequencer that includes a sequencing slide and the above-described fluidic system, wherein the flow cell is disposed on the sequencing slide.

[0108]

[0120] Finally, it should be explained that the above embodiments are used to merely illustrate, rather than limit, the technical solutions of the present application; although the present application has been described in detail in relation to preferred embodiments, those skilled in the art should understand that specific embodiments of the present application can still be modified or some technical features can be replaced by equivalents, and such equivalents shall be included in the scope of the technical solutions claimed and protected by the present application as long as they do not deviate from the spirit of the technical solutions of the present application.

Claims

1. at least two reagent reservoirs for respectively storing at least two different reagents; a flow cell for containing a sample, said flow cell being fluidly connected to at least two reagent reservoirs; a flow diversion module comprising a flow diversion structure and at least two diversion channels, wherein the flow diversion structure has a focusing port in fluid communication with the flow cell and at least two diversion ports corresponding to the at least two diversion channels, and the at least two diversion channels and the at least two reagent reservoirs are provided in one-to-one correspondence so that each reagent enters a different diversion channel; a fluid power unit fluidly connected to the shunt module, the fluid power unit being in selective fluid communication with one of the at least two shunt channels, the fluid power unit being configured to drive reagents from the reagent reservoirs into the flow cell for reaction in a forward flow direction toward the shunt module, the fluid power unit being further configured to drive reagents in a reverse flow direction from the shunt module toward the reagent reservoirs so that reagents that need to be retrieved can enter a shunt channel different from the reagents from a previous reaction, thereby avoiding cross-contamination caused by the reagents used in the previous reaction being retrieved into the flow cell; A flow path system comprising:

2. 2. The flow path system of claim 1, wherein the at least two branch channels comprise a first branch channel and a second branch channel, and the branch structure comprises a three-way tube, the three-way tube comprising a focusing port fluidly connected to the flow cell, a first branch port in fluid communication with the first branch channel, and a second branch port in fluid communication with the second branch channel.

3. The flow path system according to claim 2 , wherein the diversion module further comprises an opening / closing control valve, the opening / closing control valve being provided in the first diversion channel and / or the second diversion channel.

4. 2. The flow path system of claim 1, wherein the at least two diversion channels comprise a first diversion channel and a second diversion channel, the diversion structure comprises a first reverse valve, the first reverse valve having a first port, a second port, and a third port, the first port forming a focusing port, the second port forming a first diversion port in fluid communication with the first diversion channel, the third port forming a second diversion port in fluid communication with the second diversion channel, and the first reverse valve operative to control communication of the first port of the first reverse valve with the second port or the third port.

5. 3. The flow path system of claim 2, wherein the fluid power unit comprises an injection pump, the injection pump comprising a first power port and a second power port, the first power port being fluidly connected to the first branch channel and the second power port being fluidly connected to the second branch channel.

6. 6. The flow path system of claim 5, wherein the flow path system further comprises a waste cell, and the infusion pump further comprises a third power port, the third power port in fluid communication with the waste cell.

7. 3. The fluidic system of claim 2, wherein the fluid power unit comprises an injection pump and a second reverse valve, the injection pump having a first power port, the second reverse valve having a first port, a second port, and a third port, the first port and the second port being connected to the first branch channel and the second branch channel, respectively, and the third port being connected to the first power port of the injection pump, and the second reverse valve operating to control communication of the third port with the first port or the second port.

8. 8. The flow path system of claim 7, wherein the flow path system further comprises a waste cell, and the infusion pump further comprises a second power port, the second power port of the infusion pump communicating with the waste cell.

9. 5. The fluidic system of claim 4, wherein the fluid power unit comprises a first peristaltic pump and a second peristaltic pump, and the fluidic system further comprises a waste cell, wherein the first and second diversion channels both communicate with the waste cell, the first peristaltic pump is disposed in the first diversion channel, and the second peristaltic pump is disposed in the second diversion channel.

10. 10. The flow path system according to claim 1, further comprising a reagent selection component, the reagent selection component comprising a common hole and at least two branch holes, the at least two branch holes correspondingly connected to the at least two reagent storage containers, the common hole fluidly connected to the flow cell, and the common hole selectively communicating with one of the at least two branch holes.

11. 5. The fluid path system of claim 4, wherein the fluid power unit comprises an injection pump, and the fluid path system further comprises a waste cell and a reagent selection component, wherein the first branch channel and the second branch channel both communicate with the waste cell, the injection pump comprises a power port, and the reagent selection component comprises a common hole and a plurality of branch holes, the common hole selectively communicating with one of the plurality of branch holes, the plurality of branch holes comprising at least two reagent branch holes correspondingly communicating with the at least two reagent storage containers and a flow cell branch hole communicating with the flow cell, and the power port of the injection pump is connected to the common hole.

12. 10. The flow path system according to claim 1, further comprising a buffer reservoir for storing a buffer solution, the buffer reservoir being connected to the flow cell, and the fluid power unit being configured to drive the buffer solution in a forward flow direction from the buffer reservoir towards the splitter module.

13. 2. The flow path system of claim 1, wherein the fluid power unit is configured to drive reagent from the flow shunt module in a reverse direction toward the reagent reservoir and back into a conduit connected to an outlet end of the reagent reservoir.

14. A gene sequencer comprising a sequencing slide and the flow path system according to any one of claims 1 to 9, wherein the flow cell is disposed on the sequencing slide.

15. 10. A reagent recovery method for a flow path system according to claim 1, wherein the at least two different reagents include a first reagent and a second reagent, the at least two branch channels include a first branch channel and a second branch channel, and the reagent recovery method includes: controlling the fluid power unit to drive a first reagent in communication with a first shunt channel through a flow cell and a shunt structure into a first of the at least two shunt channels, wherein the first reagent undergoes a first reaction with the sample in the flow cell; controlling operation of the fluid power unit to drive a second reagent through the flow cell and the flow shunting structure, causing the second reagent to undergo a second reaction with the sample in the flow cell, and controlling the fluid power unit to drive the second reagent back toward the reagent reservoir after the second reaction; A reagent recovery method comprising:

16. 16. The reagent recovery method of claim 15, further comprising the step of controlling the operation of a fluid power unit to drive a buffer solution through the flow cell and the diversion structure into the first diversion channel after the first reaction, thereby performing washing.

17. 17. The reagent recovery method of claim 16, wherein the step of controlling the operation of the fluid power unit to drive a second reagent through the flow cell and the diversion structure, causing the second reagent to undergo a second reaction with the sample in the flow cell, and controlling the fluid power unit to drive the second reagent to flow back toward the reagent storage container after the second reaction includes: controlling the fluid power unit to drive the second reagent to communicate with a second diversion channel, through the flow cell and the diversion structure, and into a second of the at least two diversion channels; and controlling the fluid power unit to drive the second reagent to communicate with the second diversion channel and flow back toward the reagent storage container after the second reaction.

18. 16. The reagent recovery method of claim 15, wherein the step of controlling the operation of the fluid power unit to drive a second reagent through a flow cell and a diversion structure, causing the second reagent to undergo a second reaction with the sample in the flow cell, and controlling the fluid power unit to drive the second reagent to flow back toward the reagent storage container after the second reaction includes controlling the fluid power unit to drive the second reagent to communicate with a first diversion channel, through the flow cell and the diversion structure, and into the first diversion channel, and controlling the fluid power unit to drive the second reagent to communicate with the second diversion channel and flow back toward the reagent storage container after the second reaction.

19. 16. The reagent recovery method of claim 15, further comprising the step of controlling a fluid power unit to drive the first reagent, which is in communication with the first diversion channel, to flow back toward the reagent storage container after the first reaction, thereby causing the recovered first reagent to flow back through a conduit connected to the outlet end of the reagent storage container.

20. 16. The reagent recovery method of claim 15, wherein the step of controlling a fluid power unit to drive the second reagent to flow backward toward the reagent storage container includes the step of controlling a fluid power unit to drive the second reagent to flow backward toward the reagent storage container, thereby causing the recovered second reagent to flow backward through a conduit connected to the outlet end of the reagent storage container.

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