Micro-fluidic chip for nucleic acid detection and nucleic acid detection system

Abstract

The utility model discloses a micro-fluidic chip for nucleic acid detection and a nucleic acid detection system. The micro-fluidic chip comprises a chip body and a sealing body which are matched for use, wherein at least one nucleic acid detection unit is arranged on the chip body; each nucleic acid detection unit comprises a cracking cavity for storing a sample, a nucleic acid extraction cavity which is suitable for being communicated with the cracking cavity and is used for storing a cracking product, an amplification cavity which is suitable for being communicated with the nucleic acid extraction cavity, a quantitative cavity which is suitable for being communicated with the amplification cavity, and a mixing cavity which is suitable for being communicated with the quantitative cavity; the paper strip detection cavity is suitable for being communicated with the mixing cavity and is used for storing a test strip; wherein the mixing cavity is also suitable for being connected with a diluent storage cavity for storing an amplification product diluent; the sealing body is provided with at least one first sample adding hole which is communicated with each cracking cavity on the chip body in a one-to-one manner, and at least one second sample adding hole which is communicated with each diluent storage cavity in a one-to-one manner. According to the utility model, the nucleic acid detection efficiency can be improved, and the detection cost can be reduced.

Description

Technical Field

[0001] The utility model relates to the fields of molecular biology technology and microfluidic chips, and particularly relates to a microfluidic chip for nucleic acid detection and a nucleic acid detection system. Background Art

[0002] Traditional nucleic acid detection usually requires sending the collected samples to a well-equipped laboratory. At this time, the expensive equipment, trained staff, and the time difference between sample collection and test results make it possible that these laboratories may not be able to meet the needs of screening a large number of people, especially during the outbreak of infectious diseases.

[0003] Microfluidic chip technology is a technology that precisely controls fluids through microchannels, reaction chambers, and other functional components, and integrates and analyzes basic operation units such as sample preparation, reaction, separation, and detection in the processes of biological, chemical, and medical analysis. This technology has the advantages of controllable liquid flow, integration, small volume, high throughput, fast analysis, etc., and has been widely used in research fields such as biomedicine and environmental science.

[0004] In order to improve the convenience and real-time performance of on-site nucleic acid detection, in the prior art, there has gradually emerged, for example, a microfluidic chip for nucleic acid purification disclosed in Publication No. CN114164102, which can achieve nucleic acid binding, washing, elution, and nucleic acid recovery. However, this chip only realizes the purification and recovery of samples, and additional amplification and detection of samples are still required. For batch sample processing, its implementation efficiency is still poor.

[0005] Based on the problems existing in the above technologies, for another example, a rapid nucleic acid detection microfluidic chip disclosed in Publication No. CN115353968B combines the RPA technology with the microfluidic technology and chemiluminescence immunoassay technology by pre-placing RPA lyophilized reagents in the micro-mixing chamber and pre-placing HRP lyophilized reagents and pre-coupling antibodies in the chemiluminescence immunoassay reaction chamber, so as to achieve highly sensitive nucleic acid detection. Although nucleic acid detection can be directly realized under this technical solution, the chemiluminescence immunoassay technology is highly specialized and has a high detection cost, and requires professional training to operate.

[0006] Therefore, in view of some problems existing in the microfluidic chips for nucleic acid detection adopted in the prior art, it is necessary to further optimize the microfluidic chips for nucleic acid detection in terms of high detection efficiency and low detection cost. Summary of the Utility Model

[0007] The first object of the utility model is to provide a microfluidic chip for nucleic acid detection to solve the technical problem of improving its nucleic acid detection efficiency and reducing the detection cost at the same time.

[0008] The second object of the present utility model is to provide a nucleic acid detection system to solve the technical problems of improving the efficiency of nucleic acid detection and reducing the detection cost at the same time.

[0009] The microfluidic chip for nucleic acid detection of the present utility model is realized as follows:

[0010] A microfluidic chip for nucleic acid detection, comprising:

[0011] A chip body and a sealing body used in cooperation; wherein

[0012] At least one nucleic acid detection unit is provided on the chip body;

[0013] Each nucleic acid detection unit includes: a lysis chamber for storing a sample, a nucleic acid extraction chamber for storing a lysis product and adapted to communicate with the lysis chamber, an amplification chamber adapted to communicate with the nucleic acid extraction chamber, a quantification chamber adapted to communicate with the amplification chamber, a mixing chamber adapted to communicate with the quantification chamber, and a strip detection chamber for storing a test strip and adapted to communicate with the mixing chamber; wherein

[0014] The mixing chamber is also adapted to be connected to a dilution solution storage chamber for storing an amplification product dilution solution;

[0015] At least one first sample addition hole that is in one-to-one communication with each lysis chamber on the chip body, and at least one second sample addition hole that is in one-to-one communication with each dilution solution storage chamber are provided on the sealing body.

[0016] In an optional implementation case of the present utility model, the mixing chamber is connected to the dilution solution storage chamber through a cascading unit.

[0017] In an optional implementation case of the present utility model, the cascading unit includes a first-stage buffer chamber adapted to communicate with the dilution solution storage chamber, a second-stage buffer chamber adapted to communicate with the first-stage buffer chamber, and a third-stage buffer chamber adapted to communicate with the second-stage buffer chamber; wherein

[0018] The third-stage buffer chamber is adapted to communicate with the mixing chamber.

[0019] In an optional implementation case of the present utility model, the cascading unit includes a first-stage buffer chamber adapted to communicate with the dilution solution storage chamber and at least three siphon pipes arranged in sequence between the first-stage buffer chamber and the mixing chamber.

[0020] In an optional implementation case of the present utility model, a grinding member and / or a stirring member is provided in the lysis chamber.

[0021] In an optional implementation case of the present utility model, the nucleic acid extraction chamber is also adapted to communicate with a precipitation chamber for debris generated after sample lysis.

[0022] In an alternative embodiment of the present utility model, air holes are further provided on the sealing body.

[0023] In an alternative embodiment of the present utility model, a self-ventilation structure communicating with the air holes is further provided on the chip body;

[0024] The self-ventilation structure includes: a first communication channel communicating with the air holes, a second communication channel and a second circular blocking valve communicating with the primary buffer chamber, a third communication channel communicating with the secondary buffer chamber, a fourth communication channel, a fifth blocking valve and a fifth communication channel communicating with the tertiary buffer chamber, a twelfth communication channel communicating with the distribution channel, a fifth communication channel 4 communicating with the mixing chamber, a sixth blocking valve, an eleventh communication channel and a tenth communication channel communicating the strip detection chamber and the mixing chamber, a ninth communication channel communicating the buffer chamber and the nucleic acid extraction chamber, and a sixth communication channel, a seventh communication channel and an eighth communication channel communicating the lysis chamber, the lysis product waste liquid chamber and the strip detection chamber.

[0025] In an alternative embodiment of the present utility model, the area of the sealing body corresponding to the strip detection chamber is made of a light-transmitting material.

[0026] The nucleic acid detection system of the present utility model is implemented as follows:

[0027] A nucleic acid detection system includes: the microfluidic chip for nucleic acid detection as described above, and a centrifuge for driving the rotation of the microfluidic chip for nucleic acid detection.

[0028] By adopting the above technical solutions, the present utility model has the following beneficial effects: The microfluidic chip for nucleic acid detection of the present utility model integrates sample processing, analysis and result detection into a delicate and highly precise microfluidic chip. Users only need to simply inject the sample to achieve a highly automated and efficient sample analysis process. Compared with expensive and complex optical detection systems and traditional agarose gel electrophoresis, the test strip can achieve a visual detection result by observing the color change with the naked eye. This chip can greatly shorten the detection time, reduce the detection cost, and improve the pathogen screening and analysis efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the overall structure of the microfluidic chip for nucleic acid detection of the present utility model;

[0030] Figure 2 It is a schematic diagram of the structure of a nucleic acid detection unit of the microfluidic chip for nucleic acid detection of the present utility model;

[0031] Figure 3 It is a schematic diagram of the self-ventilation structure of a nucleic acid detection unit of the microfluidic chip for nucleic acid detection of the present utility model;

[0032] Figure 4 Structural schematic diagram of the seal body of the microfluidic chip for nucleic acid detection of the present utility model;

[0033] Figure 5 Schematic diagram of the lysis chamber of the microfluidic chip for nucleic acid detection of the present utility model under one implementation case;

[0034] Figure 6 Schematic diagram of the cascade unit of the microfluidic chip for nucleic acid detection in Embodiment 2 of the present utility model.

[0035] In the figure: 1, sample loading port; 2, lysis chamber; 3, first capillary valve; 4, lysis product waste liquid chamber; 5, nucleic acid extraction chamber; 6, second capillary valve; 7, precipitation chamber; 8, first siphon pipeline; 9, buffer chamber; 10, amplification chamber; 11, second siphon pipeline; 12, first blocking valve; 13, distribution channel; 14, third siphon pipeline; 15, fourth siphon channel; 16, second blocking valve; 17, quantification chamber; 18, obstacle; 19, amplification product waste liquid chamber; 20, mixing chamber; 21, third blocking valve; 22, fifth siphon pipeline; 23, tertiary buffer chamber; 24, fourth blocking valve; 25, sixth siphon pipeline; 26, secondary buffer chamber; 27, first circular blocking valve; 28, seventh siphon pipeline; 29, primary buffer chamber; 30, third capillary valve; 31, diluent storage chamber; 32, positioning structure; 33, strip detection chamber; 34, chip body; 35, annular structure; 36, first communication channel; 37, second communication channel; 38, second circular blocking valve; 39, third communication channel; 40, fourth communication channel; 41, fifth blocking valve; 42, fifth communication channel; 43, sixth communication channel; 44, seventh communication channel; 45, eighth communication channel; 46, ninth communication channel; 47, tenth communication channel; 48, eleventh communication channel; 49, sixth blocking valve; 50, twelfth communication channel; 51, first sample loading hole; 52, second sample loading hole; 53, air hole; 54, seal body; 55, sample lysis and extraction unit; 56, cascade unit; 57, stirring member; 58, grinding member; 59, third circular blocking valve; 60, eighth siphon pipeline; 61, ninth siphon pipeline; 62, tenth siphon pipeline; 63, fourth circular blocking valve; 64, fourth capillary valve; 65, fifth circular blocking valve. Detailed implementation manners

[0036] In order to make the content of the present utility model easier to be clearly understood, the present utility model will be further described in detail below according to specific embodiments in conjunction with the accompanying drawings.

[0037] Embodiment 1: Please refer to Figures 1 to 5As shown in the figure, this embodiment provides a microfluidic chip for nucleic acid detection, including: a chip body 34 and a sealing body 54 used in cooperation; at least one nucleic acid detection unit is provided on the chip body 34. For example, two nucleic acid detection units are designed on the chip body 34. These two nucleic acid detection units are independent of each other and do not interfere with each other. The two nucleic acid detection units can simultaneously detect 2 samples in parallel, improving the efficiency of disease screening and analysis. The sealing body 54 and the chip body 34 can be hermetically connected by means such as gluing, hot pressing, laser welding, and ultrasonic welding. Among them, in the case of glue sealing, the sealing body 54 can be a material with adhesiveness on one side or a non-adhesive material, and the sealing body 54 and the chip body 34 are bonded together through a material with adhesiveness on both sides as an intermediate layer.

[0038] In this regard, generally speaking, each nucleic acid detection unit includes: a lysis chamber 2 for storing samples, a nucleic acid extraction chamber 5 suitable for communicating with the lysis chamber 2 for storing lysis products, an amplification chamber 10 suitable for communicating with the nucleic acid extraction chamber 5, a quantification chamber 17 suitable for communicating with the amplification chamber 10, a mixing chamber 20 suitable for communicating with the quantification chamber 17, and a strip detection chamber 33 suitable for communicating with the mixing chamber 20 for storing test strips; the mixing chamber 20 is also suitable for communicating with a dilution solution storage chamber 31 for storing amplification product diluent. The samples and lysis solution in the lysis chamber 2 can be mixed by the Euler force generated by the rotation of a centrifuge, and then the samples can be fully lysed. Dry powder balls required for amplifying target molecules are pre-buried in the amplification chamber 10.

[0039] Based on the above situation, a buffer chamber 9 can be designed between the amplification chamber 10 and the nucleic acid extraction chamber 5. When multiple dry powder balls need to be pre-buried for amplification, the buffer chamber 9 can be used as one of the pre-selections to pre-bury the dry powder balls. The liquid dissolves the dry powder balls in the buffer chamber 9 and the amplification chamber 10 in sequence under the drive of external force, realizing the efficient mixing of the solution and the dry powder.

[0040] When the liquid in the above-mentioned amplification chamber 10 is exponentially amplified, the loop-mediated isothermal amplification technique, polymerase chain reaction, recombinase polymerase isothermal amplification technique, or other isothermal amplification techniques can be selected according to actual needs.

[0041] At least one first sample addition hole 51 that is in one-to-one communication with each lysis chamber 2 on the chip body 34, and at least one second sample addition hole 52 that is in one-to-one communication with each dilution solution storage chamber 31 are provided on the sealing body 54. To adapt to the usage requirements of different nucleic acid detection units on the chip body 34. Taking two nucleic acid detection units as an example, two first sample addition holes 51 and two second sample addition holes 52 are designed on the sealing body 54.

[0042] Furthermore, the nucleic acid extraction chamber 5 is also adapted to communicate with a precipitation chamber 7 for precipitating the debris generated after sample lysis. The amplification chamber 10 is also adapted to communicate with an amplification product waste liquid chamber 19. An absorbent material can be pre-placed in the amplification product waste liquid chamber 19 here to absorb the excess liquid.

[0043] In a specific and optional implementation manner, the lysis chamber 2 adopted in this embodiment can also be improved as follows: adding a lysis buffer to the lysis chamber 2 for chemical lysis. Or a grinding member 58 and / or a stirring member 57 are provided in the lysis chamber 2 to form mechanical lysis of the sample in the lysis chamber 2. That is to say, the grinding member 58 and the stirring member 57 can be designed simultaneously, or only one of them can be designed, and these situations all meet the usage requirements of this embodiment. The grinding member 58 can be glass beads or zirconia beads; the stirring member 57 can be a magnetic circular or strip-shaped magnetic rod. Which lysis method to specifically adopt can be selected according to the actual situation. For example, for Gram-positive bacteria with thick cell walls, mechanical lysis is preferably used to achieve sample lysis.

[0044] In addition, it is also necessary to explain that an air hole 53 is also provided on the sealing body 54. In this regard, for the air hole 53, the first sample adding hole 51 and the second sample adding hole 52 on the sealing body 54, they can be sealed with a sealing member. Among them, the sealing member can be a tape with adhesiveness on one side.

[0045] The area of the sealing body 54 corresponding to the test strip detection chamber 33 is made of a light-transmitting material to form an observation port. The light-transmitting material here can be polymethyl methacrylate, polydimethylsiloxane, polycarbonate, etc. The color development situation on the test strip is observed through the observation port to obtain quantitative or qualitative results. For qualitative analysis: if only the control line exists, the result of this experiment is negative; if both the control line and the test line exist, the result of this experiment is positive; if neither the control line nor the test line exists, the result of this experiment is invalid. For quantitative analysis: a preliminary quantitative result can be obtained by checking the depth of the test line, and an accurate quantitative result can be achieved by using auxiliary equipment (such as a mobile phone or a CCD camera) to quantify the color depths of the test line and the control line.

[0046] On the basis of the above structure, it is also necessary to explain that, in an optional implementation case, the mixing chamber 20 is connected to the diluent storage chamber 31 through a cascade unit 56.

[0047] Regarding the cascade unit 56 adopted in this embodiment, taking a specific implementation manner as an example in combination with the attached drawings: it includes a primary buffer chamber 29 adapted to communicate with the diluent storage chamber 31, a secondary buffer chamber 26 adapted to communicate with the primary buffer chamber 29, and a tertiary buffer chamber 23 adapted to communicate with the secondary buffer chamber 26; among them, the tertiary buffer chamber 23 is adapted to communicate with the mixing chamber 20.

[0048] In addition, it is also necessary to note that a positioning and mating structure can be designed between the sealing body 54 and the chip body 34. The positioning and mating structure can include positioning structures 32 designed on the sealing body 54 and the chip body 34 and a pair of annular structures 35 located on both sides of the positioning structure 32. The reliable mating and positioning effect between the sealing body 54 and the chip body 34 is ensured through three-point mating. Specifically, the positioning structure 32 and the annular structure 35 here can both adopt the concave-convex mating method, and this embodiment does not make an absolute limitation on this.

[0049] An auto-ventilation structure communicating with the air hole 53 is also provided on the chip body 34. The auto-ventilation structure is connected to each functional cavity in the chip body 34 to form an internal self-closed loop system. Specifically, the auto-ventilation structure includes: a first communication channel 36 communicating with the air hole 53, a second communication channel 37 and a second circular blocking valve 38 communicating with the primary buffer cavity 29, a third communication channel 39 communicating with the secondary buffer cavity 26, a fourth communication channel 40, a fifth blocking valve 41 and a fifth communication channel 42 communicating with the tertiary buffer cavity 23, a twelfth communication channel 50 communicating with the distribution channel 13, a fifth communication channel 42 communicating with the mixing cavity 20, a sixth blocking valve 49, an eleventh communication channel 48 and a tenth communication channel 47 communicating the strip detection cavity 33 and the mixing cavity 20, a ninth communication channel 46 communicating the buffer cavity 9 and the nucleic acid extraction cavity 5, a sixth communication channel 43, a seventh communication channel 44 and an eighth communication channel 45 communicating the lysis cavity 2, the lysis product waste liquid cavity 4 and the strip detection cavity 33.

[0050] The nucleic acid extraction cavity 5 is communicated with the precipitation cavity 7 through the second capillary valve 6 and is used to store the fragments generated after the sample is lysed by high-speed centrifugation. A lysis product waste liquid cavity 4 is also provided on one side of the nucleic acid extraction cavity 5, and a water-absorbing material can be pre-placed therein to absorb the excess liquid. The lysis cavity 2, the first capillary valve 3, the nucleic acid extraction cavity 5, the second capillary valve 6, the precipitation cavity 7, and the lysis product waste liquid cavity 4 together constitute the nucleic acid sample lysis and extraction unit 55 of the sample embodiment.

[0051] The nucleic acid sample enters the sample inlet 1 in the chip body 34 through the first sample addition hole 51 in the sealing body 54, and further pushes the gas in the lysis cavity 2 through the sixth communication channel 43, the seventh communication channel 44, the eighth communication channel 45, and the first capillary valve 3 into the downstream cavity. Optionally, during the liquid injection process, the lysis reagent can be injected first and then the sample, or the lysis reagent and the sample can be premixed in a test tube and then injected into the lysis cavity 2 at one time. The sample and the lysis reagent in the lysis cavity 2 can be mixed by the Euler force generated by the rotation of the motor, thereby fully lysing the sample.

[0052] The nucleic acid extraction chamber 5 is connected to the buffer chamber 9 through the first siphon valve 8, so that there is a buffering effect before the cleavage product in the nucleic acid extraction chamber 5 enters the amplification chamber 10, and the gas in the amplification chamber 10 and the buffer chamber 9 overflows to other structures through the second siphon valve 11 and the ninth connecting channel 46. Compared with the buffer chamber 9, the amplification chamber 10 far away from the positioning structure 32 is used to amplify the target molecules from the nucleic acid extraction chamber 5. Before the chip body 34 is bonded to the sealing body 54, the amplification chamber 10 is pre-embedded with dry powder balls and the like required for the amplification of the target molecules. The liquid in the nucleic acid extraction chamber 5 passes through the buffer chamber 9 to reach the amplification chamber 10 to fully dissolve the pre-embedded dry powder balls, and then exponentially amplifies.

[0053] The first capillary valve 3 located below the lysis chamber 2 and the third capillary valve 30 located between the diluent storage chamber 31 and the primary buffer chamber 29 are used to control the flow of the liquid in the lysis chamber 2 and the liquid in the diluent storage chamber 31. The amplified target sequence in the amplification chamber 10 enters the distribution channel 13 through the second siphon pipe 11 and the first blocking valve 12 to fill the quantitative structure, and then the excess liquid enters the waste liquid chamber.

[0054] The diluent enters the diluent storage chamber 31 located in the chip body 34 through the second sample loading hole 52 located in the sealing body 54; the air in the diluent storage chamber 31 passes through the third capillary valve 30, the second connecting channel 37 and the first connecting channel 36 and then is discharged into the atmosphere through the second circular blocking valve 38 connected to the air hole 53 located in the sealing body 54.

[0055] Based on the above situation, it is also necessary to explain that in order to improve the structural stability of each microvalve inside the chip body 34, the first circular blocking valve 27, the fourth blocking valve 24, the third blocking valve 21, the first blocking valve 12 and the second blocking valve 16 are respectively connected downstream of the seventh siphon pipe 28, the sixth siphon pipe 25, the fifth siphon pipe 22, the second siphon pipe 11 and the fourth siphon pipe 15 to improve the robustness of the microvalve.

[0056] Furthermore, the primary buffer chamber 29 and the secondary buffer chamber 26 are connected through the seventh siphon pipe 28 and the first circular blocking valve 27. The distance between the first circular blocking valve 27 and the chip positioning structure 32 is much greater than the distance between the siphon peak of the seventh siphon pipe 28 and the chip positioning structure 32. The liquid passing through the siphon peak is intercepted by the first circular blocking valve 27.

[0057] The secondary buffer chamber 26 and the tertiary buffer chamber 23 are connected through the sixth siphon pipe 25 and the fourth blocking valve 24. The distance between the fourth blocking valve 24 and the chip positioning structure 32 is much greater than the distance between the siphon peak of the sixth siphon pipe 25 and the chip positioning structure 32. The liquid passing through the siphon peak is intercepted under the blocking of the fourth blocking valve 24. Among them, the channel size of the fourth blocking valve 24 is slightly larger than the sixth siphon pipe 25.

[0058] The tertiary buffer chamber 23 and the mixing chamber 20 are connected through a fifth siphon pipe 22 and a third blocking valve 21. The distance between the third blocking valve 21 and the chip positioning structure 32 is much greater than the distance between the siphon peak of the fifth siphon pipe 22 and the chip positioning structure 32. The liquid passing through the siphon peak is intercepted by the blocking of the third blocking valve 21. Among them, the channel size of the third blocking valve 21 is slightly larger than that of the fifth siphon pipe 22.

[0059] The positions of the siphon peaks in the first siphon pipe 8, the second siphon pipe 11, the fourth siphon pipe 15, the third siphon pipe 14, the fifth siphon pipe 22, the sixth siphon pipe 25, and the seventh siphon pipe 28 are all arc-shaped structures and are close to the positioning structure 32 compared to the end connected to the downstream chamber.

[0060] Next, it will be described in detail with reference to the drawings. As Figure 2 and 4 shown, the running buffer is injected into the dilution liquid storage chamber 31 in the chip body 34 from the first sample injection hole 51 of the sealing body 54 with a pipette; the sample and the lysis buffer are sequentially injected into the lysis chamber 2 through the sample injection port 1 in the chip body 34 from the second sample injection hole 52 of the sealing body 54 for chemical lysis; optionally, the sample can also be directly injected into the lysis chamber 2, and mechanical lysis is performed under the cooperation of the stirring member 57 and the grinding member 58.

[0061] Subsequently, seals are used to seal the first sample addition hole 51, the second sample addition hole 52, and the air hole 53. After the sample is lysed in the lysis chamber 2, at a certain rotational speed, the running buffer in the dilution buffer storage chamber 31 breaks through the critical value of the third capillary valve 30 and enters the primary buffer chamber 29. The lysate in the lysis chamber 2 breaks through the critical value of the first capillary valve 3 and enters the nucleic acid extraction chamber 5. Among them, the excess waste liquid enters the lysate waste liquid chamber 4. At a continuous high rotational speed, the lysed sample fragments enter the precipitation chamber 7 through the second capillary valve 6. Subsequently, the running buffer in the primary buffer chamber 29 passes through the siphon peak of the seventh siphon pipe 28 under capillary action, and the liquid in the nucleic acid extraction chamber 5 passes through the siphon peak of the first siphon pipe 8 under capillary action. Immediately afterwards, when the centrifugal force is greater than the critical values of the seventh siphon pipe 28 and the first siphon pipe 8, the running buffer in the primary buffer chamber 29 enters the secondary buffer chamber 26, and the liquid in the nucleic acid extraction chamber 5 enters the amplification chamber 10 through the buffer chamber 9 to dissolve the dry powder embedded inside the chamber, and then exponential amplification is carried out. After the amplification is completed, at a certain rotational speed, the running buffer in the secondary buffer chamber 26 enters the tertiary buffer chamber 23 through the sixth siphon pipe 25 and the fourth blocking valve 24; at the same time, the amplification product in the amplification chamber 10 flows through the second siphon pipe 11 and the first blocking valve 12 and passes through the distribution channel 13 and enters the quantification chamber 17 and the waste liquid chamber in sequence. Immediately afterwards, at a certain rotational speed, the amplification product in the quantification chamber 17 enters the mixing chamber 20 through the fourth siphon channel 15 and the second blocking valve 16; at the same time, the running buffer in the tertiary buffer chamber 23 enters the mixing chamber 20 through the fifth siphon pipe 22 and the third blocking valve 21. The running buffer and the amplification product are efficiently mixed in the mixing chamber 20 through the alternating rotation mode of the motor. Here, an obstacle 18 (the shape of the obstacle 18 can be circular, rectangular, strip-shaped, and other irregular shapes) can be set in the mixing chamber 20 to increase the turbulence during the mixing of the running buffer and the amplification product, further improving the mixing efficiency of the two. The mixed liquid contacts the test strip pre-stored in the test strip detection chamber 33 through the third siphon pipe 14, thereby realizing chromatographic color development. Finally, the user can judge the positive and negative according to the color development state. Compared with expensive and complex optical detection systems and traditional agarose gel electrophoresis, the test strip can achieve a visual detection result by observing the color change with the naked eye. This chip can greatly shorten the detection time, reduce the detection cost, and improve the efficiency of pathogen screening and analysis, especially suitable for primary medical institutions, resource-limited areas, and non-professional personnel.

[0062] In summary, for the microfluidic chip of this embodiment, sample processing, analysis, and result detection are integrated into a delicate and highly precise microfluidic chip. Users only need to simply inject the sample to achieve a highly automated and efficient sample analysis process. Moreover, the overall microfluidic chip is a fully enclosed, self-ventilated, and full-process microfluidic chip. The entire chip remains sealed during sample lysis, nucleic acid extraction, amplification, and detection. The gas and liquid in the enclosed space reach a gas-liquid equilibrium state during chip operation, avoiding the risk of aerosol contamination that may occur during processes such as amplification, detection, and human factors.

[0063] Embodiment 2: Please refer to Figure 6 As shown, based on the microfluidic chip for nucleic acid detection in Embodiment 1, the microfluidic chip for nucleic acid detection provided in this embodiment has a substantially the same structure as that in Embodiment 1, except that the structure of the cascade unit 56 adopted is different.

[0064] Specifically, taking an optional case in conjunction with the attached drawings as an example, the cascade unit 56 adopted in this embodiment includes a primary buffer chamber 29 adapted to communicate with the diluent storage chamber 31, and at least three siphon pipes arranged in sequence between the primary buffer chamber 29 and the mixing chamber 20.

[0065] Specifically, in combination with the attached Figure 6 drawings, the primary buffer chamber 29 is sequentially connected to the eighth siphon pipe 60, the third circular blocking valve 59, the ninth siphon pipe 61, the fifth circular blocking valve 65, the tenth siphon pipe 62, the fourth circular blocking valve 63, and the fourth capillary valve 64. The liquid in the diluent storage chamber 31 breaks through the third capillary valve 30 and enters the primary buffer chamber 29. The liquid in the primary buffer chamber 29 sequentially passes through the eighth siphon pipe 60 and the third circular blocking valve 59, the ninth siphon pipe 61 and the fifth circular blocking valve 65, the tenth siphon pipe 62 and the fourth circular blocking valve 63 according to the optimized path, and finally, at a certain rotational speed, the liquid in the quantitative chamber 17 and the liquid in the primary buffer chamber 29 sequentially pass through the fourth capillary valve 64, the fourth siphon valve 15, and the second blocking valve 16 and enter the mixing chamber 20.

[0066] Embodiment 3: Based on the microfluidic chip for nucleic acid detection in Embodiment 1 or Embodiment 2, this embodiment provides a nucleic acid detection system, including: the microfluidic chip for nucleic acid detection in Embodiment 1 or Embodiment 2, and a centrifuge for driving the microfluidic chip for nucleic acid detection to rotate. The centrifuge here is used to drive the microfluidic chip to rotate at a high speed.

[0067] In the above specific embodiments, the purpose, technical solution and beneficial effects of the present utility model have been further described in detail. It should be understood that the above are only specific embodiments of the present utility model and are not used to limit the present utility model. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model shall be included in the protection scope of the present utility model.

[0068] In the description of the present utility model, it should be understood that the terms indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model.

[0069] In the present utility model, unless otherwise clearly defined and limited, terms such as "installation", "connection", "connection", "fixation" and other terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. It can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0070] In the description of the present utility model, it should be noted that the terms indicating the orientation or positional relationship such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the product of the present utility model is normally placed. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model. In addition, the terms "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0071] In addition, terms such as "horizontal", "vertical", "hanging" do not mean that the component is required to be absolutely horizontal or hanging, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0072] In the present utility model, unless otherwise clearly defined and limited, the first feature being above or below the second feature may include direct contact between the first and second features, or may include contact between the first and second features not directly but through additional features therebetween. Moreover, the first feature being above, on top of, and over the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being below, beneath, and under the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is less than that of the second feature.

Claims

1. A microfluidic chip for nucleic acid detection, characterized in that, Comprising: A chip body and a sealing body used in combination; Wherein At least one nucleic acid detection unit is provided on the chip body; Each of the nucleic acid detection units includes: a lysis chamber for storing a sample, a nucleic acid extraction chamber adapted to communicate with the lysis chamber for storing a lysis product, an amplification chamber adapted to communicate with the nucleic acid extraction chamber, a quantification chamber adapted to communicate with the amplification chamber, a mixing chamber adapted to communicate with the quantification chamber, and a strip detection chamber adapted to communicate with the mixing chamber for storing a test strip; wherein The mixing chamber is further adapted to be connected to a diluent storage chamber for storing an amplification product diluent; At least one first sampling hole that is in one-to-one communication with each lysis chamber on the chip body, and at least one second sampling hole that is in one-to-one communication with each diluent storage chamber are provided on the sealing body.

2. The microfluidic chip for nucleic acid detection according to claim 1, wherein The mixing chamber is connected to the diluent storage chamber through a cascading unit.

3. The microfluidic chip for nucleic acid detection according to claim 2, wherein The cascading unit includes a first buffer chamber adapted to communicate with the diluent storage chamber, a second buffer chamber adapted to communicate with the first buffer chamber, and a third buffer chamber adapted to communicate with the second buffer chamber; wherein The third buffer chamber is adapted to communicate with the mixing chamber.

4. The microfluidic chip for nucleic acid detection according to claim 2, wherein The cascading unit includes a first buffer chamber adapted to communicate with the diluent storage chamber and at least three siphon pipes arranged in sequence between the first buffer chamber and the mixing chamber.

5. The microfluidic chip for nucleic acid detection according to any one of claims 1 to 4, characterized in that A grinding member and / or a stirring member is provided in the lysis chamber.

6. The microfluidic chip for nucleic acid detection according to any one of claims 1 to 4, characterized in that, The nucleic acid extraction chamber is further adapted to communicate with a precipitation chamber for debris generated after sample lysis.

7. The microfluidic chip for nucleic acid detection according to claim 1, wherein Air holes are also provided on the sealing body.

8. The microfluidic chip for nucleic acid detection according to claim 7, wherein, A self-ventilation structure in communication with the air holes is further provided on the chip body; The self-ventilation structure includes: a first communication channel in communication with the air holes, a second communication channel and a second circular blocking valve in communication with the first buffer chamber, a third communication channel in communication with the second buffer chamber, a fourth communication channel, a fifth blocking valve and a fifth communication channel in communication with the third buffer chamber, a twelfth communication channel in communication with a distribution channel, a fifth communication channel 4 in communication with the mixing chamber, a sixth blocking valve, an eleventh communication channel and a tenth communication channel for communicating the strip detection chamber and the mixing chamber, a ninth communication channel for communicating the buffer chamber and the nucleic acid extraction chamber, and a sixth communication channel, a seventh communication channel and an eighth communication channel for communicating the lysis chamber, the lysis product waste liquid chamber and the strip detection chamber.

9. The microfluidic chip for nucleic acid detection according to claim 1, wherein The area of the sealing body corresponding to the strip detection chamber is made of a light-transmitting material.

10. A nucleic acid detection system, characterized in that, Comprising: The microfluidic chip for nucleic acid detection according to any one of claims 1 to 9, and a centrifuge for driving the rotation of the microfluidic chip for nucleic acid detection.

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