Micro-fluidic chip

Abstract

The micro-fluidic chip comprises a chip main body and a cover plate covering the chip main body, the chip main body is provided with a diluent quantitative cavity, a sample quantitative cavity, a uniform mixing cavity, a separate injection runner, a detection hole, a first capillary tube, a second capillary tube and a third capillary tube, and a flow guide structure is arranged in the uniform mixing cavity; the flow guide structure is used for guiding the diluent flowing into the uniform mixing cavity to flow into the third capillary tube earlier than the sample. Due to the fact that the flow guide structure is arranged in the uniform mixing cavity, the flow guide structure can guide the diluent flowing into the uniform mixing cavity to flow into the third capillary tube earlier than the sample flowing into the uniform mixing cavity, and the sample flowing into the uniform mixing cavity will encounter the diluent earlier in the process of flowing into the third capillary tube. The sample flowing into the uniform mixing cavity is mixed with the diluent before flowing into the third capillary tube, and then the sample flowing into the third capillary tube and finally flowing into the detection hole is diluted by the diluent, namely, the sample flowing into the detection hole is a low-concentration sample, so that the accuracy of a detection result and the detection precision are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of in vitro detection, and particularly relates to a microfluidic chip. Background Art

[0002] The microfluidic chip mainly includes a sample quantification chamber, a diluent quantification chamber, a mixing chamber, a dispensing channel, and a detection hole. The diluent quantification chamber is connected to the mixing chamber through a first capillary, the sample chamber is connected to the mixing chamber through a second capillary, the mixing chamber is connected to the dispensing channel through a third capillary, and the dispensing channel is connected to the detection hole. The sample in the sample quantification chamber and the diluent in the diluent quantification chamber need to first enter the mixing chamber for mixing. The diluent dilutes the sample, and the diluted sample then enters the detection hole for optical detection.

[0003] In current microfluidic chip products, affected by the design of the positions of each chamber, the distance between the outlet of the second capillary connected to the mixing chamber and the inlet of the third capillary connected to the mixing chamber is less than the distance between the outlet of the first capillary connected to the mixing chamber and the inlet of the third capillary connected to the mixing chamber. As a result, after the sample enters the mixing chamber, it may directly enter the detection hole through the third capillary without being mixed with the diluent, and the undiluted sample directly enters the detection hole for detection, which will affect the detection result and detection accuracy. Summary of the Invention

[0004] The present invention provides a microfluidic chip for demonstrating a mixing chamber with a flow guiding function.

[0005] According to a first aspect, in one embodiment, a microfluidic chip is provided, including a chip body and a cover plate covering the chip body. The chip body has a diluent quantification chamber, a sample quantification chamber, a mixing chamber, a dispensing channel, a detection hole, a first capillary, a second capillary, and a third capillary;

[0006] The diluent quantification chamber is used for quantifying the diluent to be introduced. The diluent quantification chamber is connected to the mixing chamber through the first capillary, and the diluent in the diluent quantification chamber can be injected into the mixing chamber through the first capillary;

[0007] The sample quantification chamber is used for quantifying the sample to be introduced. The sample quantification chamber is connected to the mixing chamber through a second capillary, and the sample in the sample quantification chamber can be injected into the mixing chamber through the second capillary;

[0008] The mixing chamber is used for mixing the sample and the diluent into a mixed solution. The mixing chamber is connected to the dispensing channel through the third capillary, and the mixed solution in the mixing chamber can be injected into the dispensing channel through the third capillary;

[0009] The dispensing flow channel is communicated with the detection hole, and the dispensing flow channel is used to divert the mixed liquid to the detection hole;

[0010] A diversion structure is arranged in the mixing cavity, and the diversion structure is used to guide the diluent flowing into the mixing cavity to flow into the third capillary tube earlier than the sample.

[0011] In one embodiment, the diversion structure includes a diversion surface extending from the outlet of the first capillary tube to the inlet of the third capillary tube, and the diversion surface is used to guide the diluent flowing into the mixing cavity to flow out to the third capillary tube earlier than the sample.

[0012] In one embodiment, at least a part of the diversion surface is arranged in the vertical direction or obliquely.

[0013] In one embodiment, at least a part of the diversion surface is a plane or a curved surface.

[0014] In one embodiment, the diversion surface includes an inflow part located at one end of the diversion surface and an outflow part located at the other end of the diversion surface. The inflow part is inclined to the liquid outlet direction of the outlet of the first capillary tube to receive and guide the diluent flowing out of the outlet of the first capillary tube, and / or the outflow part is parallel to the liquid inlet direction of the inlet of the third capillary tube to guide the diluent to flow into the inlet of the third capillary tube.

[0015] In one embodiment, the extending direction of the diversion surface is linear, curved or polyline-shaped.

[0016] In one embodiment, the diversion structure is arranged on the cover plate.

[0017] In one embodiment, the diversion structure protrudes on the cover plate, and there is a gap between the lower side of the diversion structure and the bottom of the mixing cavity, and the gap is for the liquid in the mixing cavity to flow.

[0018] In one embodiment, the diversion structure and the cover plate are an integrated structure.

[0019] In one embodiment, the flow resistance of the first capillary tube is less than that of the second capillary tube, so that the flow rate of the diluent in the first capillary tube is greater than the flow rate of the sample in the second capillary tube.

[0020] According to the second aspect, in one embodiment, a microfluidic chip is provided, which includes a chip body and a cover plate covering the chip body. The chip body has a diluent metering cavity, a sample metering cavity, a mixing cavity, a dispensing flow channel, a detection hole, a first capillary tube, a second capillary tube and a third capillary tube;

[0021] The dilution liquid metering chamber is used to meter the dilution liquid to be introduced. The dilution liquid metering chamber is communicated with the mixing chamber through the first capillary tube, and the dilution liquid in the dilution liquid metering chamber can be injected into the mixing chamber through the first capillary tube;

[0022] The sample metering chamber is used to meter the sample to be introduced. The sample metering chamber is communicated with the mixing chamber through the second capillary tube, and the sample in the sample metering chamber can be injected into the mixing chamber through the second capillary tube;

[0023] The mixing chamber is used to mix the sample and the dilution liquid into a mixed liquid. The mixing chamber is communicated with the dispensing flow channel through the third capillary tube, and the mixed liquid in the mixing chamber can be injected into the dispensing flow channel through the third capillary tube;

[0024] The dispensing flow channel is communicated with the detection hole, and the dispensing flow channel is used to dispense the mixed liquid into the detection hole;

[0025] The flow resistance of the first capillary tube is less than that of the second capillary tube, so that the flow rate of the dilution liquid in the first capillary tube is greater than the flow rate of the sample in the second capillary tube.

[0026] In one embodiment, the cross-sectional area of the first capillary tube is larger than that of the second capillary tube.

[0027] In one embodiment, the cross-sectional area of the first capillary tube is 16000 - 45000 um2, and / or the cross-sectional area of the second capillary tube is 12000 - 37500 um2.

[0028] In one embodiment, the width of the first capillary tube is greater than the width of the second capillary tube; and / or the depth of the first capillary tube is greater than the depth of the second capillary tube.

[0029] In one embodiment, the width of the first capillary tube is 200 - 300 um, and the depth of the first capillary tube is 80 - 150 um; and / or the width of the second capillary tube is 150 - 250 um, and the depth of the second capillary tube is 80 - 150 um.

[0030] In one embodiment, the length of the first capillary tube is less than the length of the second capillary tube.

[0031] In one embodiment, the length of the first capillary tube is 13 - 20 mm, and / or the length of the second capillary tube is 15 - 25 mm.

[0032] In one embodiment, the distance from the outlet of the first capillary tube to the inlet of the third capillary tube is greater than the distance from the outlet of the second capillary tube to the inlet of the third capillary tube.

[0033] For the microfluidic chip according to the above embodiments, since a flow guiding structure is provided in the mixing cavity, the flow guiding structure can guide the diluent flowing into the mixing cavity to flow into the third capillary tube earlier than the sample flowing into the mixing cavity. As a result, when the sample flowing into the mixing cavity is on its way to flow into the third capillary tube, it will surely encounter the diluent first. In other words, before the sample flowing into the mixing cavity flows into the third capillary tube, it will be mixed with the diluent. Furthermore, the sample flowing into the third capillary tube and finally into the detection hole is diluted by the diluent, that is, the sample flowing into the detection hole is a low-concentration sample, ensuring the accuracy and precision of the detection result. Description of the Drawings

[0034] Figure 1 It is a schematic structural diagram of the chip body in one embodiment;

[0035] Figure 2 It is a schematic structural diagram of the cover plate in one embodiment;

[0036] Figure 3 It is a schematic diagram showing some structural features of the microfluidic chip in one embodiment;

[0037] Figure 4 It is a schematic diagram of a partial structure of the microfluidic chip in one embodiment;

[0038] Figure 5 It is a schematic diagram of a partial structure of the microfluidic chip in one embodiment;

[0039] Figure 6 It is a schematic diagram of a partial structure of the microfluidic chip in one embodiment;

[0040] The reference numerals are as follows:

[0041] Diluent metering cavity 1, sample metering cavity 2, mixing cavity 3, dispensing flow channel 4, detection hole 5, mixed liquid detection hole 51, non-mixed liquid detection hole 52, first capillary tube 6, second capillary tube 7, third capillary tube 8, flow guiding structure 9, diluent sac cavity 10, diluent buffer cavity 11, sample buffer cavity 12.

[0042] Chip body 100, cover plate 200. Detailed Embodiments

[0043] The present invention will be further described in detail below in conjunction with the specific embodiments and the accompanying drawings. Similar elements in different embodiments are denoted by related similar element numbers. In the following embodiments, many detailed descriptions are provided to enable a better understanding of the present application. However, those skilled in the art can easily recognize that some of the features can be omitted in different situations, or can be replaced by other elements, materials, or methods. In some cases, some operations related to the present application are not shown or described in the specification, in order to avoid overwhelming the core part of the present application with excessive descriptions. For those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations based on the descriptions in the specification and the general technical knowledge in the art.

[0044] In addition, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can also be reordered or adjusted in a manner obvious to those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for clearly describing a certain embodiment, and do not mean that they are the necessary sequences, unless it is stated otherwise that a certain sequence must be followed.

[0045] The serial numbers assigned to the components in this article, such as "first", "second", etc., are only used to distinguish the described objects and do not have any sequential or technical meanings. And the "connection" and "coupling" mentioned in the present application, unless otherwise specified, both include direct and indirect connection (coupling).

[0046] The microfluidic chip of the present application has a mixing chamber, which is connected to the outlet of the first capillary, the outlet of the second capillary, and the inlet of the third capillary. The outlet of the first capillary is used to introduce the diluent into the mixing chamber, the outlet of the second capillary is used to introduce the sample into the mixing chamber, the mixing chamber is used to mix the sample and the diluent to form a mixed solution, and the inlet of the third capillary is used to export the mixed solution in the mixing chamber. The distance between the outlet of the first capillary and the inlet of the third capillary is greater than the distance between the outlet of the second capillary and the inlet of the third capillary.

[0047] To prevent the sample introduced into the mixing chamber from the outlet of the second capillary from entering the inlet of the third capillary earlier than the diluent introduced into the mixing chamber from the outlet of the first capillary, so that the sample enters the third capillary earlier than the diluent. Two solutions can be adopted. The first solution is to directly guide the diluent entering the mixing chamber to the inlet of the third capillary without guiding the sample entering the mixing chamber. In this way, under the guidance, the diluent will flow into the third capillary first. In this solution, a diversion structure can be set in the mixing chamber. The diversion structure is located in the area between the outlet of the first capillary and the inlet of the third capillary. The diversion structure can divert the diluent entering the mixing chamber to the inlet of the third capillary. Without diversion, even if the sample entering the mixing chamber is closer to the inlet of the third capillary, it will not directly flow into the inlet of the third capillary under the action of centrifugation.

[0048] The second solution is to design the flow resistance of the first capillary to be less than that of the second capillary, so that the flow rate of the diluent in the first capillary is greater than that of the sample in the second capillary, making the diluent enter the mixing chamber earlier than the sample, and then making the diluent enter the inlet of the third capillary earlier than the sample.

[0049] The above two solutions can be used alone or in combination, both of which can effectively control the diluent to enter the third capillary earlier than the sample to ensure that the samples entering the detection have all passed through the diluent.

[0050] Please refer to Figures 1 to 4 , in an embodiment, a microfluidic chip is provided. The microfluidic chip mainly includes a chip body 100 and a cover plate 200. The cover plate 200 can be fixed to one side of the chip body 100 by bonding or other means. The chip body 100 has a diluent metering chamber 1, a sample metering chamber 2, a mixing chamber 3, a dispensing channel 4, a detection hole 5, a first capillary 6, a second capillary 7 and a third capillary 8. The chip body 100 also has structures such as a diluent bladder chamber 10, a diluent buffer chamber 11, and a sample buffer chamber 12. The holes, chambers, channels and other structures on the chip body 100 are all located on the side of the chip body 100 facing the cover plate 200. The cover plate 200 hermetically covers the holes, chambers, channels and other structures on the chip body 100.

[0051] The diluent cavity 10 is located in the middle of the microfluidic chip. The diluent cavity 10 is used to install and place the diluent sac. The diluent metering cavity 1 is arranged close to the diluent cavity 10 and is communicated with the diluent cavity 10. The diluent in the diluent cavity 10 can flow into the diluent metering cavity 1. The diluent metering cavity 1 is used to measure the diluent required for detection. The diluent metering cavity 1 can also be communicated with the diluent cavity 10 through the diluent buffer cavity 11, and the diluent buffer cavity 11 plays a buffering role. The diluent buffer cavity 11 is located on the circumferential outer side of the connection with the diluent cavity 10, and the diluent metering cavity 1 is located on the circumferential outer side of the diluent buffer cavity 11, that is, the diluent buffer cavity 11 and the diluent metering cavity 1 are successively away from the rotation center of the microfluidic chip; when the microfluidic chip makes a centrifugal motion, the diluent can enter the diluent buffer cavity 11 first through centrifugal force and then enter the diluent metering cavity 1.

[0052] One end of the diluent metering cavity 1 is communicated with the diluent buffer cavity 11, and the other end of the diluent metering cavity 1 is connected with a diluent remaining cavity, which is used to accommodate the excessive remaining diluent.

[0053] The sample buffer cavity 12 is provided with a sample injection port, and the sample metering cavity 2 is communicated with the sample injection cavity. Among them, one end of the sample buffer cavity 12 is provided with a sample injection port, and the other end of the sample buffer cavity 12 far from the sample injection port is communicated with the sample metering cavity 2. The sample metering cavity 2 is located on the circumferential outer side of the sample buffer cavity 12, and the sample metering cavity 2 is farther from the rotation center of the microfluidic chip than the sample buffer cavity 12; when the microfluidic chip makes a centrifugal motion, the sample can enter the sample metering cavity 2 through centrifugal force.

[0054] The mixing cavity 3 is respectively communicated with the diluent metering cavity 1 and the sample metering cavity 2. The mixing cavity 3 is communicated with the diluent metering cavity 1 through the first capillary 6, and the mixing cavity 3 is communicated with the sample metering cavity 2 through the second capillary 7. The first capillary 6 can suck the diluent in the diluent metering cavity 1 into the mixing cavity 3, and the second capillary 7 can suck the sample in the sample metering cavity 2 into the mixing cavity 3. The mixing cavity 3 is used to mix the sample and the diluent to form a mixed solution. The diluent is used to dilute the sample, and the mixed solution is a sample solution with a lower concentration.

[0055] The detection holes 5 include a mixed solution detection hole 51 and a non-mixed solution detection hole 52. The mixed solution detection hole 51 is used to store the mixed solution formed by mixing the sample and the diluent. There are multiple mixed solution detection holes 51, and the multiple mixed solution detection holes 51 can be used for the detection of the same or different items. There are also multiple non-mixed solution detection holes 52, and the non-mixed solution detection holes 52 can be used to store the remaining sample or the remaining diluent to achieve the detection for other different purposes.

[0056] The dispensing runner 4 communicates with the mixing chamber 3, and the mixing chamber 3 communicates with a plurality of mixed liquid detection holes 51 through the dispensing runner 4. One end of the dispensing runner 4 can communicate with the mixing chamber 3 through the third capillary 8, and the third capillary 8 can suck the mixed liquid into the dispensing runner 4. The dispensing runner 4 has a plurality of branch pipelines, and the dispensing runner 4 communicates with a plurality of mixed liquid detection holes 51 respectively through the branch pipelines. Under the action of centrifugal force, the mixed liquid in the dispensing runner 4 can be dispensed into a plurality of mixed liquid detection holes 51.

[0057] In this embodiment, the mixing chamber 3 communicates with the outlet of the first capillary 6, the outlet of the second capillary 7, and the inlet of the third capillary 8 respectively. The linear distance between the outlet of the first capillary 6 and the inlet of the third capillary 8 is greater than the linear distance between the outlet of the second capillary 7 and the inlet of the third capillary 8, that is, the outlet of the second capillary 7 is closer to the inlet of the third capillary 8 than the outlet of the first capillary 6.

[0058] A diversion structure 9 is provided in the mixing chamber 3. The diversion structure 9 is arranged in the area between the outlet of the first capillary 6 and the inlet of the third capillary 8. The diversion structure 9 is used to guide the diluent flowing into the mixing chamber 3 from the outlet of the first capillary 6 to directly flow to the inlet of the third capillary 8, so that the diluent entering the mixing chamber 3 flows to the inlet of the third capillary 8 before the sample, and then when the sample flows to the inlet of the third capillary 8, it will inevitably mix with the diluent, realizing the dilution of the sample, avoiding the direct flow of the high-concentration sample into the inlet of the third capillary 8, and ensuring the accuracy of the detection.

[0059] The diversion structure 9 can be arranged on the cover plate 200. The diversion structure 9 and the cover plate 200 can be an integrated structure. The diversion structure 9 is a convex structure of the cover plate 200. The diversion structure 9 can also be fixed on the cover plate 200 by means of bonding, clamping, etc. In the thickness direction of the microfluidic chip (the direction perpendicular to the rotation surface), the outlet of the first capillary 6 and the inlet of the third capillary 8 are closer to the cover plate 200, that is, the outlet of the first capillary 6 and the inlet of the third capillary 8 are closer to the upper end of the cover plate 200 located in the mixing chamber 9. Therefore, arranging the diversion structure 9 on the cover plate 200 can be more conducive to guiding the diluent flowing out of the outlet of the first capillary 6 into the inlet of the third capillary 8.

[0060] In one embodiment, the diversion structure 9 can be installed in the mixing chamber 3 of the chip body 100 through structures such as a bracket. The bracket can be connected to the side wall or the bottom wall of the mixing chamber 3. The bracket fixes and supports the diversion structure 9 at the upper end of the mixing chamber 3, so that the diversion structure 9 and the outlet of the first capillary 6 and the inlet of the third capillary 8 are at the same height position. This installation method can also achieve the installation and fixation of the diversion structure 9. Of course, the diversion structure 9 can also be an integrated structure with the chip body 100, that is, the diversion structure 9, the bracket, and the chip body 100 are integrally formed.

[0061] In one embodiment, the diversion structure 9 is simultaneously fixed to both the chip body 100 and the cover plate 200. A part of the diversion structure 9 is connected to the chip body 100. The diversion structure 9 is connected to the chip body 100 through a bracket, and the fixed installation of the diversion structure 9 can also be achieved.

[0062] In one embodiment, the diversion structure 9 has a diversion surface which extends from the outlet of the first capillary 6 towards the inlet of the third capillary 8. One end of the diversion surface is close to or abuts against the outlet of the first capillary 6, and the other end of the diversion surface is close to or abuts against the inlet of the third capillary 8. The diluent flowing into the mixing chamber 3 from the outlet of the first capillary 6 will flow along the diversion surface to the inlet of the third capillary 8.

[0063] In one embodiment, at least a part of the diversion surface can be arranged vertically or obliquely. The vertical direction is perpendicular to the cover plate 200, and the inclined direction is inclined relative to the cover plate 200. For example, the whole diversion surface is arranged vertically, or the whole diversion surface is arranged obliquely, or a part of the diversion surface is arranged vertically and the other part of the diversion surface is arranged obliquely. The diversion surface arranged vertically or obliquely can block the flow of the diluent, that is, after the diluent flows into the mixing chamber 3, it will hit the vertically or obliquely arranged diversion surface, and then the diversion surface can play a role in guiding the flow direction of the diluent. If the diversion surface is arranged horizontally, that is, the diversion surface is parallel to the cover plate 200, the diversion surface cannot block and guide the flow direction of the diluent.

[0064] In one embodiment, the diversion surface can also be a plane or a curved surface. For example, the whole diversion surface is a plane extending from the outlet of the first capillary 6 towards the inlet of the third capillary 8. The diversion surface with a plane structure can play a good role in diversion. The whole diversion surface can also be a curved surface extending from the outlet of the first capillary 6 towards the inlet of the third capillary 8. The curved surface is preferably a concave curved surface, and the concave curved surface can form a semi-open guiding flow channel, which can guide the diluent to the inlet of the third capillary 8. Of course, the diversion surface can also be a combined surface of a plane and a curved surface. For example, a part of the diversion surface is a plane and the other part is a curved surface. The diluent is first guided by the diversion surface with a plane structure and then guided by the diversion surface with a curved surface, and the diversion of the diluent can also be realized.

[0065] In one embodiment, the diversion surface includes an inflow portion at one end of the diversion surface and an outflow portion at the other end of the diversion surface. The inflow portion of the diversion surface is located at one end close to the outlet of the first capillary, and the outflow portion of the diversion surface is at one end close to the inlet of the third capillary. The inflow portion of the diversion surface is inclined towards the liquid outflow direction of the outlet of the first capillary, that is, the inflow portion of the diversion surface is blocked on the path of the diluted liquid outflow, so that the diluted liquid flowing into the mixing chamber 3 can be carried and guided by the inflow portion of the diversion surface. The outflow portion of the diversion surface is parallel to the liquid inflow direction of the inlet of the third capillary, so that the diluted liquid guided by the diversion surface can quickly and accurately enter the inlet of the third capillary.

[0066] Of course, the shapes and directions of the inflow portion and the outflow portion of the diversion surface can also be set in other forms. For example, the inflow portion of the diversion surface can be a curved structure, which is a bend in the length direction of the diversion surface, so that the tangent direction of the inflow portion of the diversion surface is aligned with the outlet of the first capillary 6, and the diluted liquid flowing out of the outlet of the first capillary 6 can also be carried and guided by the inflow portion; or, the outflow portion of the diversion surface can be set as a curved structure, which is a bend in the length direction of the diversion surface, so that the tangent direction of the outflow portion of the diversion surface is aligned with the inlet of the third capillary 8, and the outflow portion can also quickly and accurately introduce the diluted liquid into the third capillary 8.

[0067] In one embodiment, the diversion surface can be a straight-line type, a curve type or a broken-line type structure, etc. This shape is a structure extending along the diversion direction, such as Figure 4 As shown, the diversion surface is a straight-line type structure. The diversion surface of the straight-line type structure has the shortest length, so that the flow path of the diverted diluted liquid is the shortest, and the diluted liquid can be quickly diverted to the inlet of the third capillary 8, having the best diversion effect. As Figure 5 As shown, although the diversion path of the curve-type diversion surface is relatively long, it can reduce the impact force of the diluted liquid flowing into the diversion surface, ensure the flow rate of the diluted liquid, and also improve the diversion speed. As Figure 6 As shown, the broken-line type diversion surface can also play a role in diversion, forming a unique diversion method; the broken-line type diversion surface can include two or more sections of broken lines, which can be selected and set according to needs. When the number of sections of the broken-line type diversion surface is large, it can be approximated to the curve-type diversion surface, which can reduce a certain impact force of the diluted liquid entering the diversion surface and improve the diversion speed.

[0068] In one embodiment, the diversion structure 9 is located at the upper end of the mixing chamber 3, and there is a gap between the lower side of the diversion structure 9 and the bottom of the mixing chamber 9. This gap allows the liquid in the mixing chamber 3 to flow, so as to facilitate the mixing of the diluted liquid and the sample, and allow the mixed liquid on the other side of the mixing chamber 3 to enter the third capillary 9. The lower end of the diversion structure can also extend to the bottom of the mixing chamber 3, and holes or openings for avoiding channels are provided in the lower half of the diversion structure, which can also realize the flow of the sample and the diluted liquid in the mixing chamber 3.

[0069] In one embodiment, the flow resistance of the first capillary 6 is less than that of the second capillary 7, that is, the flow rate of the diluent in the first capillary 6 is greater than the flow rate of the sample in the second capillary 7, or when the diluent can flow in the first capillary 6, the sample does not flow or is temporarily unable to flow in the second capillary 7, so that the diluent can enter the mixing chamber 3 before the sample, and further the diluent can flow into the inlet of the third capillary 8 before the sample. With such a setting, the sample can be mixed with the diluent before entering the third capillary 8, so that the sample entering the third capillary 8 and the final detection hole 5 is a low-concentration sample after dilution, so as to ensure the accuracy of the detection.

[0070] The flow resistance of the capillary can be changed by changing the pore diameter of the capillary. Therefore, the pore diameter of the first capillary 6 is larger than that of the second capillary 7, and this pore diameter refers to the cross-sectional area of the first capillary 6 and the second capillary 7. It should be noted that the pore diameter of the first capillary 6 being larger than that of the second capillary 7 refers to the average pore diameter. When both the first capillary 6 and the second capillary 7 are capillaries with non-uniform pore diameters, the average pore diameter of the first capillary 6 is larger than the average pore diameter of the second capillary 7, which can make the flow resistance of the first capillary 6 greater than that of the second capillary 7.

[0071] The cross-sectional area of the first capillary 6 can be 16000 - 45000 um 2 , for example, the cross-sectional area of the first capillary 6 is 40000 um 2 . The cross-sectional area of the second capillary 7 can be 12000 - 37500 um 2 , for example, the cross-sectional area of the second capillary 7 is 20000 um 2 . The flow rate ratio of the diluent and the sample can be controlled by setting the ratio of the cross-sectional areas of the first capillary 6 and the second capillary 7.

[0072] In one embodiment, the cross-sectional areas of the first capillary 6 and the second capillary 7 are determined by the width and depth. Therefore, there are the following several situations that can make the cross-sectional area of the first capillary 6 larger than that of the second capillary 7.

[0073] The width of the first capillary 6 is greater than the width of the second capillary 7, and the depth of the first capillary 6 is equal to the depth of the second capillary 7. The width of the first capillary 6 is equal to the width of the second capillary 7, and the depth of the first capillary 6 is greater than the depth of the second capillary 7. The width of the first capillary 6 is greater than the width of the second capillary 7, and the depth of the first capillary 6 is greater than the depth of the second capillary 7. All these three situations make the cross-sectional area of the first capillary 6 larger than that of the second capillary 7, that is, the flow resistance of the first capillary 6 is less than that of the second capillary 7.

[0074] The width of the first capillary 6 can be 200 - 300 um. For example, the width of the first capillary 6 is 250 um; the depth of the first capillary 6 can be 80 - 150 um in height. For example, the depth of the first capillary 6 is 100 um in height. The width of the second capillary 7 can be 150 - 250 um. For example, the width of the second capillary 7 is 200 um; the depth of the second capillary 7 can be 80 - 150 um. For example, the depth of the second capillary 7 is 90 um.

[0075] In one embodiment, the lengths of the first capillary 6 and the second capillary 7 are adjusted, and the length of the first capillary 6 is set to be less than that of the second capillary 7. Under the same flow resistance adjustment of the first capillary 6 and the second capillary 7, or when the flow resistance of the first capillary 6 is less than that of the second capillary 7 and the length of the first capillary 6 is less than that of the second capillary 7, the flow transmission time of the diluent in the first capillary 6 is less than that of the sample in the second capillary 7. Similarly, the diluent can enter the mixing chamber 3 prior to the sample, so that the diluent entering the mixing chamber 3 flows to the inlet of the third capillary 8 prior to the sample. Then, when the sample flows to the inlet of the third capillary 8, it will necessarily be mixed with the diluent, realizing the dilution of the sample, avoiding the direct inflow of the high - concentration sample into the inlet of the third capillary 8, and ensuring the accuracy of the detection.

[0076] The above uses specific examples to elaborate on the present invention, which is only used to help understand the present invention and is not intended to limit the present invention. For those skilled in the technical field of the present invention, based on the idea of the present invention, several simple deductions, deformations or substitutions can also be made.

Claims

1. A microfluidic chip, characterized in that, it includes a chip body (100) and a cover plate (200) covering the chip body (100). The chip body (100) has a diluent metering chamber (1), a sample metering chamber (2), a mixing chamber (3), a dispensing flow channel (4), a detection hole (5), a first capillary (6), a second capillary (7), and a third capillary (8); The diluent metering chamber (1) is used to meter the diluent to be introduced. The diluent metering chamber (1) is communicated with the mixing chamber (3) through the first capillary (6), and the diluent in the diluent metering chamber (1) can be injected into the mixing chamber (3) through the first capillary (6); The sample metering chamber (2) is used to meter the sample to be introduced. The sample metering chamber (2) is communicated with the mixing chamber (3) through the second capillary (7), and the sample in the sample metering chamber (2) can be injected into the mixing chamber (3) through the second capillary (7); The mixing chamber (3) is used to mix the sample and the diluent into a mixed solution. The mixing chamber (3) is communicated with the dispensing flow channel (4) through the third capillary (8), and the mixed solution in the mixing chamber (3) can be injected into the dispensing flow channel (4) through the third capillary (8); The dispensing flow channel (4) is communicated with the detection hole (5), and the dispensing flow channel (4) is used to divert the mixed solution to the detection hole (5); A diversion structure (9) is arranged in the mixing chamber (3), and the diversion structure (9) is used to guide the diluent flowing into the mixing chamber (3) to flow into the third capillary (8) earlier than the sample.

2. The microfluidic chip according to claim 1, characterized in that, the diversion structure (9) includes a diversion surface extending from the outlet of the first capillary (6) to the inlet of the third capillary (8), and the diversion surface is used to guide the diluent flowing into the mixing chamber (3) to flow out to the third capillary (8) earlier than the sample.

3. The microfluidic chip according to claim 2, characterized in that, at least a part of the diversion surface is arranged vertically or obliquely.

4. The microfluidic chip according to claim 2, characterized in that, at least a part of the diversion surface is a plane or a curved surface.

5. The microfluidic chip according to claim 2, characterized in that, the diversion surface includes an inflow part at one end of the diversion surface and an outflow part at the other end of the diversion surface. The inflow part is inclined to the liquid outlet direction of the outlet of the first capillary to receive and guide the diluent flowing out of the outlet of the first capillary, and / or, the outflow part is parallel to the liquid inlet direction of the inlet of the third capillary to guide the diluent to flow into the inlet of the third capillary.

6. The microfluidic chip according to claim 2, characterized in that, the extending direction of the diversion surface is linear, curved or polyline-shaped.

7. The microfluidic chip according to claim 1, characterized in that, the diversion structure (9) is arranged on the cover plate (200).

8. The microfluidic chip according to claim 7, It is characterized in that, the diversion structure (9) protrudes from the cover plate (200), and there is a gap between the lower side of the diversion structure (9) and the bottom of the mixing cavity (3), and the liquid in the mixing cavity (3) flows through the gap.

9. The microfluidic chip according to claim 7, It is characterized in that, the diversion structure (9) and the cover plate (200) are of an integral structure.

10. The microfluidic chip according to any one of claims 1 to 9, It is characterized in that, the flow resistance of the first capillary (6) is less than that of the second capillary (7), so that the flow rate of the diluent in the first capillary (6) is greater than the flow rate of the sample in the second capillary (7).

11. A microfluidic chip, It is characterized in that, comprising a chip body (100) and a cover plate (200) covering the chip body (100), the chip body (100) having a diluent metering cavity (1), a sample metering cavity (2), a mixing cavity (3), a dispensing channel (4), a detection hole (5), a first capillary (6), a second capillary (7) and a third capillary (8); the diluent metering cavity (1) is used for metering the diluent to be introduced, the diluent metering cavity (1) communicates with the mixing cavity (3) through the first capillary (6), and the diluent in the diluent metering cavity (1) can be injected into the mixing cavity (3) through the first capillary (6); the sample metering cavity (2) is used for metering the sample to be introduced, the sample metering cavity (2) communicates with the mixing cavity (3) through the second capillary (7), and the sample in the sample metering cavity (2) can be injected into the mixing cavity (3) through the second capillary (7); the mixing cavity (3) is used for mixing the sample and the diluent into a mixed solution, the mixing cavity (3) communicates with the dispensing channel (4) through the third capillary (8), and the mixed solution in the mixing cavity (3) can be injected into the dispensing channel (4) through the third capillary (8); the dispensing channel (4) communicates with the detection hole (5), and the dispensing channel (4) is used for dispensing the mixed solution into the detection hole (5); the flow resistance of the first capillary (6) is less than that of the second capillary (7), so that the flow rate of the diluent in the first capillary (6) is greater than the flow rate of the sample in the second capillary (7).

12. The microfluidic chip according to claim 11, It is characterized in that, the cross-sectional area of the first capillary (6) is larger than that of the second capillary (7).

13. The microfluidic chip according to claim 12, It is characterized in that, The cross-sectional area of the first capillary (6) is 16000 - 45000 um 2 , and / or, the cross-sectional area of the second capillary (7) is 12000 - 37500 um 2 .

14. The microfluidic chip according to claim 11, It is characterized in that, the width of the first capillary (6) is greater than the width of the second capillary (7); and / or, the depth of the first capillary (6) is greater than the depth of the second capillary (7).

15. The microfluidic chip according to claim 14, It is characterized in that, The width of the first capillary (6) is 200 - 300 um, and the depth of the first capillary (6) is 80 - 150 um; and / or, the width of the second capillary (7) is 150 - 250 um, and the depth of the second capillary (7) is 80 - 150 um.

16. The microfluidic chip according to claim 11, characterized in that, the length of the first capillary (6) is less than the length of the second capillary (7).

17. The microfluidic chip according to claim 16, characterized in that, the length of the first capillary (6) is 13 - 20 mm, and / or, the length of the second capillary (7) is 15 - 25 mm.

18. The microfluidic chip according to any one of claims 1 to 17, characterized in that, the distance between the outlet of the first capillary (6) and the inlet of the third capillary (8) is greater than the distance between the outlet of the second capillary (7) and the inlet of the third capillary (8).

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