Microfluidic Chip for Sorting Living Cells

Abstract

The present invention relates to a microfluidic chip for sorting living cells. A sample flow channel communicates with the liquid supply end of a sorting flow channel, an intake air flow channel, a target flow channel, and a non-target flow channel are connected to the liquid discharge end of the sorting flow channel. The angle between the target flow channel and the sorting flow channel is 100° - 130°, the angle between the non-target flow channel and the sorting flow channel is 100° - 140°, and the intersection point of the axis of the intake air flow channel and the axis of the sorting flow channel is 0.02 mm to 0.05 mm away from the intersection point of the three of the sorting flow channel, the target flow channel, and the non-target flow channel. The microfluidic chip in this solution can expand the sorting area, extend the residence time of cells in the sorting area, and can accurately blow target cells into the target flow channel by an air flow, so the accuracy of cell sorting is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of live cell sorting, and more specifically, to a microfluidic chip for sorting live cells.

Background Art

[0002] As research in the field of cells progresses, our understanding of cells is increasing. When studying cells, cell sorting is an important link in the research of cell physiology and pathology. Currently, the main technical means of cell sorting in the market is to combine flow cytometry and a microfluidic chip to sort target cells from a cell population. The cell sorting chip can use a piezoelectric, magnetic, or pneumatic drive structure to drive cells to change their movement trajectories. Compared with other methods, the pneumatic drive structure causes the least damage to cells. Therefore, when it is necessary to sort active cells, a cell sorting chip with a pneumatic drive structure is often selected to sort target cells. For example, in existing sorting devices that can simultaneously detect multiple fluorescence signals inside cells, the microfluidic chip includes a detection region, a sorting region, an air inlet, a waste liquid pool, and a target cell pool. The detection region and the sorting region are connected via a first cell flow path, the sorting region and the waste liquid pool are connected via a second cell flow path, the air inlet and the sorting region are connected via a gas flow path, and the target cell pool and the sorting region are connected via a sorting flow path. The first cell flow path, the second cell flow path, the gas flow path, and the sorting flow path are arranged in a cross shape around the sorting region. This solution injects gas into the gas flow path to blow the target cells into the sorting flow path, so the damage to the target cells caused by the gas when changing the path of the target cells is smaller. However, since the area of the sorting region is too small in this solution, if the flow rate of the cell liquid in the sorting flow path is too fast, the residence time of the target cells in the sorting region is too short, and it is difficult to ensure that the air flow in the gas flow path accurately blows the target cells into the sorting flow path, resulting in low cell sorting accuracy.

Summary of the Invention

Means for Solving the Problems

[0003] In the above existing technical solutions, since the sorting area of the microfluidic chip is too small, when the flow rate of the cell fluid in the sorting channel is too fast, the residence time of the target cells in the sorting area is too short, and it is difficult to ensure that the air flow in the gas channel blows the target cells accurately into the sorting channel. Therefore, in order to solve the problem that the accuracy of cell sorting is not high, the present invention provides a microfluidic chip for sorting live cells. In this solution, the area of the sorting area can be further enlarged, and the passing time of the cells in the sorting area can be extended. Therefore, the target cells can be accurately blown into the target channel, and the accuracy of cell sorting can be improved.

[0004] The technical solution adopted in the present invention is a microfluidic chip for sorting live cells, which includes a sample area, a sample channel communicating with the sample area, an electromagnetic valve, an intake air channel communicating with the electromagnetic valve, a target cell pool, a target channel communicating with the target cell pool, a non-target cell pool, a non-target channel communicating with the non-target cell pool, and a sorting channel. The sample channel communicates with the liquid supply end of the sorting channel, the target channel and the non-target channel communicate with the liquid discharge end of the sorting channel, the intake air channel communicates with the sorting channel, and is located at the end near the liquid discharge port of the sorting channel. The intake air channel and the non-target channel are located on one side of the sorting channel, the target channel is located on the other side of the sorting channel, the angle between the target channel and the sorting channel is 100° - 130°, the angle between the non-target channel and the sorting channel is 100° - 140°, the axis of the intake air channel is perpendicular to the axis of the sorting channel, and the distance d between the intersection of the axis of the intake air channel and the axis of the sorting channel and the intersection of the three of the sorting channel, the target channel and the non-target channel is 0.02 mm - 0.05 mm. The cell sorting area is the end of the sorting channel that intersects with the target channel, the non-target channel and the intake air channel.

[0005] When the microfluidic chip operates, target cells and non-target cells in the sample region ride on the flow of the cell fluid and enter the sample flow path, where they are arranged in a single straight line. As the cell fluid continues to flow forward, the target cells and non-target cells enter the sorting flow path. The target cell signal identification device identifies the cells that enter the sorting flow path. When a cell is identified as a target cell, it controls the electromagnetic valve to pump gas into the intake flow path. When the target cell moves to the sorting region, the gas in the intake flow path can move to the sorting region and blow the target cell into the target flow path. When a cell is identified as a non-target cell, the electromagnetic valve does not pump gas into the intake flow path. After the non-target cell moves to the sorting region, it continues to flow into the non-target flow path along with the cell fluid.

[0006] In this solution, the target flow path, non-target flow path, and intake flow path are provided so as to intersect the sorting flow path. When the distance d between the intersection of the axis of the intake flow path and the axis of the sorting flow path and the intersection of the three of the intake flow path, target flow path, and non-target flow path is 0.02 mm - 0.05 mm, by increasing the length of the sorting region, the residence time of the target cells in the sorting region becomes longer, the appropriate timing for pumping gas into the gas flow path becomes larger, the operation of blowing the target cells into the target flow path by the gas is completed, and the sorting accuracy of the target cells becomes higher.

[0007] When the gas in the intake air passage enters the sorting region, the gas applies a deflecting force perpendicular to the original path of the cells to the cells. After the target cells receive the deflecting force provided by the gas, the moving path of the target cells changes and becomes a parabolic path moving into the target cell passage. The shape of this parabola is determined by the flow velocity of the original cells and the magnitude of the intake air pressure. The angle between the two asymptotes of this parabola is the angle between the sorting passage and the target passage. When the target cells move within the sorting region, if the distance that the target cells move along the axial direction of the sorting passage is d, the target cells enter the target cell passage, the moving direction of the target cells is parallel to the axis of the target passage, the distance d is 0.02 mm - 0.05 mm, and the angle between the target passage and the sorting passage is 100° - 130°, it is necessary to ensure that the target cells can smoothly enter the target cell passage and the moving direction of the target cells is parallel to the axial direction of the target cell passage. Also, the deflecting force required to change the path of the target cells when the angle between the target passage and the sorting passage is 100° - 130° is smaller than the deflecting force required to change the path of the target cells when the target passage is perpendicular to the sorting passage. Even when the intake air pressure in the present application is smaller than the intake air pressure in the prior art, the cell sorting operation can be completed. The lower the intake air pressure, the smaller the damage to the target cells caused by the gas. Therefore, compared with the prior art, the present application causes less damage to the target cells. At the same time, when the angle between the non-target passage and the sorting passage is 100° - 140°, after the target cells receive the deflecting force provided by the gas in the intake air passage, the angle between the moving direction of the target cells and the axis of the non-target passage increases, further preventing the target cells from entering the non-target passage.

[0008] Preferably, the sorting channel includes a first channel and a second channel. The diameter of the first channel is 0.1 mm - 0.12 mm, and the diameter of the second channel is 0.18 mm - 0.2 mm. The first channel communicates with the sample channel, and the second channel communicates with the target channel, the non-target channel, and the intake channel. Since the diameter of the second channel is larger than that of the first channel, not only can the moving speed of the cells in the second channel be slowed down, but also the gas flow in the gas channel can be prevented from moving towards the first channel. When a part of the gas flow moves towards the first channel, this part of the gas flow cannot pass through the connection end of the second channel and the first channel, and it can be prevented that the cells are impacted by the backflow and damaged.

[0009] Preferably, the end of the second channel connected to the first channel is tapered. Since the connection part between the first channel and the second channel is tapered, the sample liquid in the first channel can gently enter and fill the second channel.

[0010] Preferably, an arc chamfer is provided between the second flow path, the intake flow path, the non-target flow path, and the target flow path. The arc chamfer between the second flow path and the intake flow path is the first chamfer, the chamfer between the intake flow path and the non-target flow path is the second chamfer, the chamfer between the non-target flow path and the target flow path is the third chamfer, and the chamfer between the target flow path and the second flow path is the fourth chamfer. The radius of the first chamfer is 0.08 mm - 0.1 mm, the radius of the second chamfer is 0.08 mm - 0.1 mm, the radius of the third chamfer is 0.12 mm - 0.15 mm, and the radius of the fourth chamfer is 0.18 mm - 0.2 mm. On the side wall where the second flow path, the intake flow path, the non-target flow path, and the target flow path intersect, an arc chamfer is provided at the intersection. Since the curvature of the chamfer coincides with the parabolic movement path of the cell, it can play a guiding role for the movement path of the cell, and even when the cell contacts the side wall, the arc chamfer at the intersection of the side wall does not damage the cell. As a result of experimental measurement, when the radius of the first chamfer is 0.08 mm - 0.1 mm, the radius of the second chamfer is 0.08 mm - 0.1 mm, the radius of the third chamfer is 0.12 mm - 0.15 mm, and the radius of the fourth chamfer is 0.18 mm - 0.2 mm, the guiding role of the chamfer for the cell is maximally exerted.

[0011] Preferably, the sample flow path includes a cell flow path and a sheath fluid flow path, the sample region includes a mixed cell region and a sheath fluid region, the cell flow path communicates with the mixed cell region, the sheath fluid flow path communicates with the sheath fluid region, and the sheath fluid flow path and the cell flow path intersect at the liquid supply end of the sorting flow path. There are two sheath fluid flow paths, and the two sheath fluid flow paths are respectively located on opposite sides of the cell flow path and are symmetrically arranged with the axis of the cell flow path as the axis of symmetry. The diameter of the sheath fluid flow path is the same as the diameter of the cell flow path, and the diameter of the non-target flow path is twice the diameter of the target flow path. The sheath fluid can wrap the cells so that they flow into the detection region of the cytometer in a single straight-line arrangement. Since there are two sheath fluid flow paths, which are respectively located on both sides of the cell flow path, the cells flowing into the sorting flow path are located in the center of the sorting flow path. Since the diameter of the sheath fluid flow path is the same as the diameter of the cell flow path and the diameter of the non-target flow path is twice the diameter of the target flow path, the ratio of the cell suspension and the sheath fluid on both sides thereof after entering the sorting flow path is 1:1:1. When there is no external interference in the liquid in the sorting flow path, the sheath fluid closer to the target flow path flows into the target flow path, and the cell suspension and the sheath fluid on the other side flow into the non-target flow path, and the guiding operation of the inflow of non-target cells into the non-target flow path is automatically completed.

[0012] Preferably, the length of the target flow path is 5 mm or less. Since the air pressure of the gas pumped into the intake flow path should not be too high, if it is too high, the gas entering the microfluidic chip will cause crosstalk throughout the flow path. The pushing force of the gas on the target cells is sufficient for the target cells to move a long distance in the target flow path. If the target flow path is too long, the target cells will stay in the target flow path and cannot reach the target cell pool. Therefore, the length of the target flow path cannot be too long. As a result of experimental measurement, when the length of the target flow path is 5 mm or less, due to the pushing force of the gas on the target cells, the target cells can smoothly pass through the target flow path and enter the target cell pool.

[0013] Preferably, the angle between the sheath liquid flow path and the cell flow path is 25 to 35°. The sheath liquid flow path is provided with a meandering flow resistance segment for reducing the flow velocity of the sheath liquid in the sheath liquid flow path. As the angle between the sheath liquid flow path and the cell flow path increases, the impact of the sheath liquid flow on the cell liquid flow after the sheath liquid and the cell liquid merge becomes larger, and the cells in the cell liquid flow are impacted. As a result of experimental measurement, if the angle between the sheath liquid flow path and the cell flow path is 25° to 35°, the sheath liquid can be gently mixed with the cell liquid. The shape of the flow resistance is serpentine. When the sheath liquid passes through the serpentine sheath liquid flow path, the kinetic energy of the sheath liquid decreases, the flow velocity of the sheath liquid decreases, and further the flow velocity of the sample liquid entering the first flow path becomes slower, and the moving speed of the cells becomes lower.

[0014] Compared with the prior art, the beneficial effect of the present invention is that the microfluidic chip in this solution does not damage the cells when performing cell sorting. In this solution, since the cell sorting area is expanded, the residence time of the target cells in the cell sorting area increases, and there are more appropriate timings for pumping. If the pumping is too slow, it can prevent the target cells from entering the non-target cell pool, improve the accuracy of cell sorting, and when using a gas with a lower air pressure, the goal of pushing the target cells into the target flow path can be achieved. The sorting flow path can reduce the moving speed of the cells and further prevent the reverse flow of the gas, so that the accuracy of cell sorting can be further improved and cell damage can be avoided. On the side walls where the second flow path, the intake air flow path, the non-target flow path, and the target flow path intersect, an arc chamfer is provided at the intersection to guide the cells entering the sorting area.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0016] The accompanying drawings are for illustrative purposes only and are not to be construed as limiting this patent. Some members of the accompanying drawings may be omitted, enlarged, or reduced to better explain the present embodiment and do not represent the dimensions of the actual product. Those skilled in the art will understand that some well-known structures and their descriptions may be omitted in the accompanying drawings. The positional relationships shown in the drawings are for illustrative purposes only and are not to be construed as limiting this patent.

[0017] Identical or similar reference numerals in the drawings of the embodiments of the present invention correspond to identical or similar parts. In the description of the present invention, the orientation or positional relationships indicated by terms such as "upper", "lower", "left", "right", "long", "short", etc. are the orientation or positional relationships shown based on the drawings and are for the purpose of easily explaining the present invention and simplifying the description only, and do not indicate or imply that the mentioned devices or elements must have a specific orientation and be constructed and operated in a specific orientation. Therefore, the terms used to describe the positional relationships in the drawings are for illustrative purposes only and are not to be construed as limiting this patent. Those skilled in the art can understand the specific meanings of the above terms according to specific situations.

[0018] Hereinafter, the technical solution of the present invention will be described in more detail through specific embodiments in conjunction with the accompanying drawings.

[0019] Example 1 FIG. 1 - FIG. 2 are Example 1 of a microfluidic chip for sorting live cells, including a sample region, a sample flow path communicating with the sample region, an electromagnetic valve, an intake flow path 1 communicating with the electromagnetic valve, a target cell pool 5, a target flow path 2 communicating with the target cell pool 5, a non - target cell pool 6, a non - target flow path 3 communicating with the non - target cell pool 6, and a sorting flow path 4. The sample flow path communicates with the liquid supply end of the sorting flow path 4, the target flow path 2 and the non - target flow path 3 communicate with the liquid discharge end of the sorting flow path 4, the intake flow path 1 communicates with the sorting flow path 4 and is located at an end near the liquid discharge port of the sorting flow path 4. The intake flow path 1 and the non - target flow path 3 are located on one side of the sorting flow path 4, and the target flow path 2 is located on the other side of the sorting flow path 4. The angle between the target flow path 2 and the sorting flow path 4 is 120°, the angle between the non - target flow path 3 and the sorting flow path 4 is 128°, the axis of the intake flow path 1 is perpendicular to the axis of the sorting flow path 4, and the distance d between the intersection of the axis of the intake flow path 1 and the axis of the sorting flow path 4 and the intersection of the three of the sorting flow path 4, the target flow path 2 and the non - target flow path 3 is 0.05 mm. The sorting region is the end of the sorting flow path 4 that intersects with the target flow path 2, the non - target flow path 3 and the intake flow path 1.

[0020] In the operating principle or process of this example, when the microfluidic chip operates, target cells and non - target cells in the sample region ride on the flow of the cell fluid and enter the sample flow path, and are arranged in a single straight line in the sample flow path. As the cell fluid continues to flow forward, the target cells and non - target cells enter the sorting region through the sorting flow path 4. The target cell signal identification device identifies the cells entering the sorting flow path 4. When a cell is identified as a target cell, the electromagnetic valve is controlled to pump gas into the intake flow path 1. When the target cell moves to the sorting region at the end of the sorting flow path 4, the gas in the intake flow path 1 can move to the sorting region and blow the target cell into the target flow path. When a cell is identified as a non - target cell, the electromagnetic valve does not pump gas into the intake flow path 1. After the non - target cell moves to the sorting region at the end of the sorting flow path 4, it continues to flow into the non - target flow path 3 along with the cell fluid.

[0021]

Table 1

[0022] The cell sorting chip used in the control group is a microfluidic chip of a sorting device for simultaneously detecting multiple fluorescence signals in cells in the prior art, while the microfluidic chip used in this application is the microfluidic chip described in this solution. Comparing Control Group 1 and Control Group 2 with Application 1 and Application 2 of this application, for the same target cells, under the same intake air pressure and cell flow rate, the accuracy of cell sorting in this application is much higher than that in the control group. Comparing Control Group 1 and Application 1 with Control Group 2 and Application 2 of this application, under the same cell flow rate, the higher the intake air pressure, the higher the accuracy of cell sorting. However, comparing Control Group 1 and Control Group 2 with Application 1 and Application 2 of this application, the experimental air pressure of the two groups decreases by the same amount, and the accuracy of cell sorting in the control group fluctuates more greatly than that in this application. As can be seen from the above experimental data, by enlarging the cell sorting area and adjusting the angle between the target flow path and the sorting flow path, the accuracy of cell sorting can be significantly improved. When driving and deflecting the target cells using a smaller air pressure, the influence of air pressure fluctuations on the accuracy of cell sorting is small, and good cell sorting results can be obtained.

[0023] The beneficial effect of this embodiment is that in this solution, since the cell sorting area is enlarged, the residence time of the target cells in the cell sorting area increases, the appropriate timing of pumping is increased, and because the pumping is too slow, it is possible to prevent the target cells from entering the non-target cell pool, thereby improving the sorting accuracy of the cells. Furthermore, when driving and deflecting the cells, using a gas with a smaller air pressure can achieve the goal of pushing the target cells into the target flow path. The smaller the air pressure of the gas, the less damage to the target cells caused by the gas flow, and the higher the activity of the target cells.

[0024] Example 2 As shown in FIGS. 1-3, Example 2 of the microfluidic chip for sorting living cells further limits the structure of the sorting flow path 4 and the sorting area based on Example 1.

[0025] Specifically, the sorting channel 4 includes a first channel 401 and a second channel 402. The diameter of the first channel 401 is 0.1 mm, and the diameter of the second channel 402 is 0.2 mm. The first channel 401 communicates with the sample channel, and the second channel 402 communicates with the target channel 2, the non-target channel 3, and the intake channel 1.

[0026] Specifically, the end portion of the first channel 401 connected to the second channel 402 is tapered.

[0027] Specifically, an arc chamfer is provided between the second channel 402, the intake channel 1, the non-target channel 3, and the target channel 2. The arc chamfer between the second channel 402 and the intake channel 1 is the first chamfer 7, the chamfer between the intake channel 1 and the non-target channel 3 is the second chamfer 8, the chamfer between the non-target channel 3 and the target channel 2 is the third chamfer 9, and the chamfer between the target channel 2 and the second channel 402 is the fourth chamfer 10. The radius of the first chamfer 7 is 0.1 mm, the radius of the second chamfer 8 is 0.1 mm, the radius of the third chamfer 9 is 0.15 mm, and the radius of the fourth chamfer 10 is 0.2 mm.

[0028] The beneficial effects of this embodiment are as follows. Since the diameter of the second flow path 402 is larger than that of the first flow path 401, not only can the moving speed of cells in the second flow path 402 be slowed down, but also the gas flow in the intake flow path can be prevented from moving in the direction of the first flow path 401. When a part of the gas flow moves towards the first flow path 401, this part of the gas flow cannot pass through the connection end between the second flow path 402 and the first flow path 401, and the cells can be prevented from being impacted by the backflow and causing cell damage. Since the connection part between the first flow path 401 and the second flow path 402 is tapered, the sample liquid in the first flow path 401 can gently enter and fill the second flow path 402. On the side walls where the second flow path 402, the intake flow path 1, the non-target flow path 3, and the target flow path 2 intersect, in order to guide the cells entering the sorting area, an arc chamfer is provided at the intersection. Since the shape of the chamfer is the same as the parabolic movement path of the cells, it can play a role in guiding the cells flowing into the sorting area, making it easier for non-target cells to flow into the non-target flow path 3 and for target cells to flow into the target flow path 2.

[0029] Example 3 As shown in FIGS. 1-3, Example 3 of the microfluidic chip for sorting living cells further limits the sample flow path, the target flow path 2, and the non-target flow path 3 based on Example 1 or Example 2.

[0030] Specifically, the sample flow path includes a cell flow path 11 and a sheath liquid flow path 12. The sample area includes a mixed cell area 13 and a sheath liquid area 14. The cell flow path 11 communicates with the mixed cell area 13, the sheath liquid flow path 12 communicates with the sheath liquid area 14, and the sheath liquid flow path 12 and the cell flow path 11 intersect at the liquid supply end of the sorting flow path 4. There are two sheath liquid flow paths 12, and the two sheath liquid flow paths 12 are respectively located on opposite sides of the cell flow path 11 and are symmetrically arranged with the axis of the cell flow path 12 as the axis of symmetry. The diameters of the sheath liquid flow path 12 and the cell flow path 11 are the same, and the diameter of the non-target flow path 3 is twice the diameter of the target flow path 2.

[0031] Specifically, the length of the target flow path 2 is 4 mm or less. The angle between the sheath liquid flow path 12 and the cell flow path 11 is 25°. A meandering flow resistance segment (not shown) for reducing the flow velocity of the sheath liquid in the sheath liquid flow path 12 is provided in the sheath liquid flow path 12.

[0032] The beneficial effects of this embodiment are as follows. Since the diameter of the sheath liquid flow path 12 is the same as that of the cell flow path 11, and the diameter of the non-target flow path 3 is twice that of the target flow path 2, the ratio of the cell suspension to the sheath liquids on both sides thereof after entering the sorting flow path 4 is 1:1:1. When there is no external interference in the liquid in the sorting flow path 4, the sheath liquid closer to the target flow path 2 flows into the target flow path 2, and the cell suspension and the sheath liquid on the other side flow into the non-target flow path 3, automatically completing the guiding operation for the inflow of non-target cells into the non-target flow path 3. When the length of the target flow path 2 is 4 mm, due to the pushing force of the gas on the target cells, the target cells can smoothly pass through the target flow path 2 and enter the target cell pool 5. As the angle between the sheath liquid flow path 12 and the cell flow path 11 increases, the impact of the sheath liquid flow on the cell liquid flow after the sheath liquid and the cell liquid merge becomes greater, impacting the cells in the cell liquid flow. As a result of experimental measurement, when the angle between the sheath liquid flow path 12 and the cell flow path 11 is 25°, the sheath liquid can be gently mixed with the cell liquid. The shape of the flow resistance is serpentine. When the sheath liquid passes through the serpentine sheath liquid flow path 12, the kinetic energy of the sheath liquid decreases, the flow velocity of the sheath liquid decreases, and further the flow velocity of the sample liquid entering the first flow path 401 slows down, and the moving speed of the cells decreases.

[0033] Obviously, the above embodiments of the present invention are only examples for clear explanation and do not limit the embodiments of the present invention. A person skilled in the art can make other different forms of deformation or modification based on the above description. It is not necessary and impossible to cover all embodiments here. Any changes, equivalent replacements, and improvements made within the spirit and principle of the present invention should all be included in the protection scope of the present invention.

Claims

1. A sample region, a sample flow path communicating with the sample region, an electromagnetic valve, an intake flow path (1) communicating with the electromagnetic valve, a target cell pool (5), a target flow path (2) communicating with the target cell pool (5), a non-target cell pool (6), a non-target flow path (3) communicating with the non-target cell pool (6), and a sorting flow path (4), wherein the sample flow path communicates with the liquid supply end of the sorting flow path (4), the target flow path (2) and the non-target flow path (3) communicate with the liquid discharge end of the sorting flow path (4), the intake flow path (1) communicates with the sorting flow path (4), is located at an end portion close to the liquid discharge port on the sorting flow path (4), the target flow path (2) is located on one side of the sorting flow path (4), the intake flow path (1) and the non-target flow path (3) are located on the other side of the sorting flow path (4), the angle between the target flow path (2) and the sorting flow path (4) is 100° - 130°, the angle between the non-target flow path (3) and the sorting flow path (4) is 100° - 140°, the axis of the intake flow path (1) is perpendicular to the axis of the sorting flow path (4), and the intersection point of the axis of the intake flow path (1) and the axis of the sorting flow path (4) is 0.02 mm to 0.05 mm away from the intersection point of the three of the sorting flow path (4), the target flow path (2) and the non-target flow path (3). A microfluidic chip for sorting living cells, characterized by this.

2. The sorting flow path (4) includes a first flow path (401) and a second flow path (402), the diameter of the first flow path 401 is 0.1 mm - 0.12 mm, the diameter of the second flow path (402) is 0.18 mm - 0.2 mm, the first flow path (401) communicates with the sample flow path, and the second flow path (402) communicates with the target flow path (2), the non-target flow path (3) and the intake flow path (1). A microfluidic chip for sorting living cells according to Claim 1, characterized by this.

3. The end portion connected to the first flow path (401) on the second flow path (402) is tapered. A microfluidic chip for sorting living cells according to Claim 2, characterized by this.

4. An arcuate chamfer is provided between the second flow path (402), the intake air flow path (1), the non-target flow path (3), and the target flow path (2). The arcuate chamfer between the second flow path (402) and the intake air flow path 1 is the first chamfer (7), the chamfer between the intake air flow path (1) and the non-target flow path (3) is the second chamfer (8), the chamfer between the non-target flow path (3) and the target flow path (2) is the third chamfer (9), and the chamfer between the target flow path (2) and the second flow path (402) is the fourth chamfer (10). The microfluidic chip for sorting live cells according to claim 2, characterized in that.

5. The radius of the first chamfer (7) is 0.08 mm - 0.1 mm, the radius of the second chamfer (8) is 0.08 mm - 0.1 mm, the radius of the third chamfer (9) is 0.12 mm - 0.15 mm, and the radius of the fourth chamfer (10) is 0.18 mm - 0.2 mm. The microfluidic chip for sorting live cells according to claim 4, characterized in that.

6. The sample flow path includes a cell flow path (11) and a sheath liquid flow path (12). The sample region includes a mixed cell region (13) and a sheath liquid region (14). The cell flow path (11) communicates with the mixed cell region (13), the sheath liquid flow path (12) communicates with the sheath liquid region (14), and the sheath liquid flow path (12) and the cell flow path (11) intersect at the liquid supply end of the sorting flow path (4). The microfluidic chip for sorting live cells according to claim 1, characterized in that.

7. There are two of the sheath liquid flow paths (12). The two sheath liquid flow paths (12) are respectively located on opposite sides of the cell flow path (11), and are symmetrically arranged with the axis of the cell flow path (11) as the axis of symmetry. The diameter of the sheath liquid flow path (12) is the same as the diameter of the cell flow path (11), and the diameter of the non-target flow path (3) is twice the diameter of the target flow path (2). The microfluidic chip for sorting live cells according to claim 6, characterized in that.

8. The length of the target flow path is 5 mm or less. The microfluidic chip for sorting live cells according to claim 7, characterized in that.

9. The angle between the sheath liquid flow path (12) and the cell flow path (11) is 25 - 35°. The microfluidic chip for sorting live cells according to claim 7, characterized in that.

10. The microfluidic chip for sorting living cells according to claim 9, wherein the sheath liquid flow path (12) is provided with a meandering flow resistance segment (not shown) for reducing the flow velocity of the sheath liquid in the sheath liquid flow path (12).

Images