Microfluidic quantitative detection device

Abstract

The utility model provides a microfluidic quantitative detection device which comprises a sample tube, a quantitative sample introduction device and a reaction tube, the quantitative sample introduction device is provided with a gas-liquid exchange area, when the quantitative sample introduction device and the reaction tube are combined into a whole, a sample in the sample tube can be quantitatively transferred into the reaction tube through the quantitative sample introduction device; by setting the position of the gas-liquid exchange groove, the groove opening is located in the lateral opening of the quantitative sampling device, and the lower bottom edge of the groove opening is flush with the plane where the liquid outlet hole is located, so that the gas-liquid exchange effect is improved, exhaust channels are formed in the gas-liquid exchange groove and the liquid reaction area of the reaction pipe, and a flow guide module is arranged at the bottom of the quantitative sampling device. The control precision of the gas-liquid exchange capacity is improved, so that the accuracy of automatically and quantitatively transferring the sample in a closed environment is improved, the pollution of aerosol in the environment to the sample is effectively avoided, and the accuracy and sensitivity of a detection result are ensured.

Description

Technical Field

[0001] This utility model relates to the field of nucleic acid detection, specifically to a sample detection device, and more particularly to a microfluidic quantitative detection device. Background Technology

[0002] Nucleic acid testing methods typically involve multiple steps, including quantitative sampling, sample pretreatment, amplification reaction, and fluorescence detection. Therefore, these steps usually need to be completed step by step using multiple devices. If there are many samples to be tested, or even tens of thousands, a lot of manpower and resources need to be invested to distribute the work of each step. This undoubtedly increases the cost and testing cycle. Moreover, the tedious, monotonous, and boring steps can easily lead to operational errors.

[0003] Current procedures typically involve sampling first, then quantitatively transferring the sample to a PCR tube or microfluidic chip using a pipette for nucleic acid amplification, followed by fluorescence detection. This process is not only more cumbersome but also exposes the sample directly to the environment, making it susceptible to aerosol contamination and affecting the accuracy of the results. Furthermore, for highly infectious viruses, such as the novel coronavirus, which spread rapidly, poor sealing during sampling can easily lead to infection of sampling personnel. Therefore, a device that can automatically perform quantitative sample transfer in a sealed environment is needed to address these issues. While fully automated equipment can complete all the above steps, its high cost prevents widespread adoption.

[0004] CN209327056U provides a supporting device for quantitative sampling and dilution of microfluidic chips. It is equipped with a quantitative airbag, and quantitative sampling is achieved by external force pressing the quantitative airbag. The accuracy of this quantitative method is directly related to the external force on the quantitative airbag, making it difficult to achieve precise quantification.

[0005] Therefore, a microfluidic quantitative detection device with a simple structure and low cost that can automatically transfer samples quantitatively to the reaction tube in a sealed environment and can be detected immediately after the reaction is urgently needed. Utility Model Content

[0006] To address the aforementioned problems, this invention provides a microfluidic quantitative detection device, comprising a sample tube, a quantitative injection device, and a reaction tube. The quantitative injection device is equipped with a gas-liquid exchange zone. When the quantitative injection device and the reaction tube are integrated, the sample in the sample tube can be quantitatively transferred to the reaction tube through the quantitative injection device. By positioning the gas-liquid exchange tank so that its opening is located at the side opening of the quantitative injection device, with the bottom edge of the tank opening flush with the plane of the liquid outlet, the gas-liquid exchange effect is improved. Exhaust channels are provided from the liquid reaction zone of the gas-liquid exchange tank and the reaction tube, respectively. A flow guiding module is provided at the bottom of the quantitative injection device to improve the control accuracy of the gas-liquid exchange volume, thereby improving the accuracy of automatic quantitative sample transfer in a closed environment, effectively avoiding aerosol contamination of the sample in the environment, and ensuring the accuracy and sensitivity of the detection results.

[0007] On the one hand, this utility model provides a microfluidic quantitative detection device, which includes a sample tube, a quantitative injection device and a reaction tube. The sample tube is used to collect samples. When the sample tube, the quantitative injection device and the reaction tube are detachably combined into one unit, a seal can be achieved. At this time, the sample in the sample tube can be quantitatively transferred to the reaction tube through the quantitative injection device.

[0008] The sample tube described in this invention refers to a reagent tube used to store collected samples for testing. In some methods, the sample tube may also be pre-filled with a pretreatment solution, including diluents, lysis buffers, etc. When performing nucleic acid testing, the sample tube may be pre-filled with lysis buffer for pretreatment such as lysis of the sample collected by the sampling swab to extract nucleic acid. In some methods, at the beginning of sampling, the swab is first removed to collect the sample, and then the swab containing the sample is inserted into the pretreatment solution of the sample tube, whereby the sample in the swab enters the pretreatment solution to form a sample solution.

[0009] In some methods, to detect target nucleic acids in a sample solution, the sample solution in the sample tube needs to be quantitatively transferred to a reaction tube for nucleic acid amplification, thus enabling nucleic acid detection. This quantitative transfer refers to transferring a specific volume of sample solution into the reaction tube. Inaccurate quantification, resulting in too much or too little sample solution entering the reaction tube, will directly lead to inaccurate detection results.

[0010] The quantitative transfer of sample solution must be completed in a sealed environment. Therefore, the sample needs to be quantitatively transferred from the sample tube to the reaction tube with the assistance of a quantitative injection device. When the sample tube, quantitative injection device and reaction tube are combined into one unit, the whole device is in a closed state, thereby avoiding the influence of aerosols in the external environment on the sample solution and avoiding the spillage of infectious viruses contained in the sample solution that could cause infection to personnel.

[0011] Preferably, the quantitative injection device includes a pre-assembled or installed filter or nucleic acid purification membrane. During sample transfer, as the sample passes through the quantitative transfer device, the nucleic acid is simultaneously filtered and purified during the quantitative transfer process.

[0012] It is understandable that the microfluidic quantitative detection device of this invention is not only applicable to nucleic acid detection, but also to the detection of other types of molecules such as proteins and antibodies. The sample tube is used for sample collection, and the reaction tube is used for sample enrichment, extraction and detection.

[0013] In some embodiments, the microfluidic quantitative detection device also includes a sampling swab, which is used to collect various biological samples such as saliva, sweat, and blood, and can also be used to collect other non-biological samples.

[0014] Furthermore, the quantitative injection device is provided with a gas-liquid exchange zone; the gas-liquid exchange zone is used to complete the gas-liquid exchange within the quantitative injection device, thereby helping the sample to be transferred from the quantitative injection device to the reaction tube; the quantitative injection device limits the amount of liquid transferred into the reaction tube by limiting the amount of gas used for gas-liquid exchange in the gas-liquid exchange zone.

[0015] When the sample solution in the sample tube flows into the reaction tube through the quantitative injection device, because the device is closed, the sample solution needs to complete gas-liquid exchange in the gas-liquid exchange zone. This means that as the liquid flows downwards, the gas needs to be expelled upwards so that the sample solution can flow smoothly into the reaction tube. The more sample solution that can complete gas-liquid exchange, the more sample solution flows into the reaction tube. Simultaneously, because the device is closed, the space used for gas storage is fixed, so the amount of gas available for gas-liquid exchange is also fixed, and the volume of sample solution that can flow into the reaction tube is also fixed. Even if the volume of sample solution in the sample tube increases, the amount of sample solution that can flow into the reaction tube remains constant, and the remaining sample solution cannot flow into the reaction tube. This ensures that the amount of sample amplified in the sample solution is fixed, guaranteeing the accuracy of the target nucleic acid detection results in the sample solution.

[0016] In other words, the sample liquid flows into the quantitative injection device under the action of gravity. It needs to overcome a certain air pressure and discharge a certain volume of gas into the closed space. The gas in the closed space is compressed. When the pressure of the compressed gas and the force that the liquid can overcome the air pressure to enter the reaction tube reach equilibrium, that is, when the weight of the sample liquid and the air pressure are the same, the sample liquid can no longer flow into the reaction tube. Since the weight of the sample liquid is basically the same, the amount of liquid entering the reaction tube through the quantitative injection device each time is also fixed. This is the quantitative injection principle of the quantitative injection device provided by this utility model.

[0017] Furthermore, the gas-liquid exchange zone includes a gas-liquid exchange tank, the opening of which is located at the lateral opening of the quantitative injection device; when the quantitative injection device and the reaction tube are combined into one unit, the opening is sealed by the reaction tube wall.

[0018] The gas-liquid exchange tank is designed to ensure sufficient gas-liquid exchange during the process of sample liquid flowing into the quantitative injection device and before it flows out. The tank opening is longitudinally spaced along the side wall of the quantitative injection device, and the opening is relatively long, ensuring that gas-liquid exchange occurs almost entirely within the tank before the sample exits the device. The more thorough the gas-liquid exchange, the more accurate the quantitative control of the sample liquid will be.

[0019] When the quantitative injection device and the reaction tube are combined into one unit, although the inlet is sealed by the reaction tube wall, the sample liquid entering the gas-liquid exchange tank can still achieve sufficient gas-liquid exchange due to the setting of the first exhaust channel connecting to the gas-liquid exchange tank.

[0020] Furthermore, the gas-liquid exchange zone also includes a first exhaust channel, the inlet of which is connected to the gas in the gas-liquid exchange tank.

[0021] The first exhaust channel starts from the gas-liquid exchange tank and extends upward along the outer wall of the quantitative injection device. When the sample liquid is injected, excess gas in the gas-liquid exchange tank needs to be exhausted. Since the outer wall of the quantitative injection device at this part is in close contact with the reaction tube, the gas can only be exhausted upward along the channel formed between the groove of the first exhaust channel and the inner wall of the reaction tube. Moreover, this channel is curved and meanders upward, which provides more buffering for the exhaust process, avoids sudden large-volume rapid exhaust from affecting the accuracy of quantification, and improves the precision of quantitative injection.

[0022] Furthermore, the quantitative injection device also includes an inlet and an outlet; the inlet is matched with the opening size of the sample tube; the sample enters the quantitative injection device through the inlet and is then quantitatively discharged into the reaction tube through the outlet.

[0023] During normal use, the quantitative injection device is inserted vertically into the reaction tube. The upper end of the quantitative injection device has an injection port, and the lower bottom surface has an outlet hole.

[0024] In some methods, the outlet orifice is a small hole. After the sample liquid is quantitatively discharged from the outlet orifice into the reaction tube, some excess sample liquid may remain above the outlet or inside the quantitative injection device. To prevent this excess sample liquid from communicating with the liquid inside the reaction tube through the outlet orifice, potentially affecting the sample below the outlet and thus the test results, the sample liquid size needs to be set as small as possible, just enough to allow the liquid to flow out. Excess sample liquid remains within the quantitative injection device. Because the plane of the outlet orifice is relatively large while the outlet orifice itself is small, the excess sample liquid is essentially unable to enter the outlet orifice, thus not affecting the sample detection process inside the reaction tube and ensuring the accuracy of the test results.

[0025] Furthermore, the bottom edge of the opening of the gas-liquid exchange tank is flush with the plane where the liquid outlet is located.

[0026] The opening of the gas-liquid exchange tank extends all the way to the plane of the liquid outlet. Therefore, all the sample liquid in the quantitative injection device can complete the full gas-liquid exchange in the gas-liquid exchange tank before flowing out of the liquid outlet. Moreover, this design makes the gas-liquid exchange tank larger, making it easier for the sample liquid to undergo gas-liquid exchange and improving the accuracy of quantification.

[0027] Furthermore, when the quantitative injection device and the reaction tube are combined into one unit, a liquid reaction zone is left at the bottom of the reaction tube; the sample enters the liquid reaction zone after being quantitatively discharged by the quantitative injection device; the gas-liquid exchange zone also includes a second exhaust channel, and the inlet of the second exhaust channel is connected to the gas in the liquid reaction zone.

[0028] After the quantitative injection device and the reaction tube are combined into one unit, the quantitative injection device cannot extend into the bottom of the reaction tube. Therefore, a part of the space at the bottom of the reaction tube is reserved for quantitatively storing the sample to be reacted and detected. This part of the space is the liquid reaction zone.

[0029] Because the liquid reaction zone is enclosed, when the sample liquid enters the liquid reaction zone through the outlet, corresponding gas also needs to be discharged. Therefore, a second exhaust channel is required in the liquid reaction zone. The inlet of the second exhaust channel is located at the bottom of the quantitative injection device, which is directly below the liquid reaction zone. This exhaust channel is directly connected to the gas in the liquid reaction zone and then forms an upward-extending groove along the outer wall of the quantitative injection device. Since the quantitative injection device is tightly fitted to the reaction tube at this location, a channel is formed between the groove of the second exhaust channel and the inner wall of the reaction tube. Gas can be discharged upwards along this channel, which is curved and meandering upwards, providing more buffering during the exhaust process and preventing sudden, large-volume, rapid exhaust from affecting the accuracy of the quantitative injection.

[0030] Furthermore, the quantitative injection device is equipped with a flow guiding device at the lower end to guide the liquid discharged from the outlet to the liquid reaction zone; the liquid reaction zone is pre-loaded with reaction reagents for detecting the sample.

[0031] Because the outlet of the quantitative injection device is relatively small, sample liquid can easily accumulate in or around the outlet. Installing a flow guiding device can help quickly guide this accumulated sample liquid into the liquid reaction zone. During the process of entering the liquid reaction zone, sample liquid may splash and remain at the top of the zone, or it may splash and remain at the air inlet of the second exhaust channel, causing blockage and affecting the accuracy of quantitative injection. Therefore, by installing a flow guiding device to smoothly guide the sample liquid accumulated near the outlet, the air inlet of the second exhaust channel, and the top of the liquid reaction zone into the liquid reaction zone, the accuracy of quantitative injection can be significantly improved.

[0032] In some methods, the liquid reaction zone can pre-store amplification reagents for amplifying the target nucleic acid. These reagents include, but are not limited to, amplification reagents for ERA, RPA, LAMP, NEAR, NASBA, HAD, TMA, SAT, RCR, etc., and can be in liquid or solid form. Solid forms include, but are not limited to, spherical, powdered, tablet, or block-shaped preparations obtained through lyophilization, drying, or air drying. The probes of the amplification reagents are also attached with fluorescent markers to indicate the quantity of target nucleic acid in the sample solution. After a quantitative amount of sample solution flows into the liquid reaction zone, it can be mixed with the amplification reagents and undergo an amplification reaction for nucleic acid detection.

[0033] Furthermore, the flow guiding device includes a first flow guiding module, a second flow guiding module, and a third flow guiding module; the first flow guiding module is provided with a first flow guiding channel to guide the sample flowing out of the liquid outlet to the liquid reaction zone; the second flow guiding module is used to guide the sample splashed out of the liquid reaction zone back to the liquid reaction zone; the third flow guiding module is used to guide the sample splashed out of the liquid reaction zone to the outer surface of the first flow guiding module, and then guide it to the liquid reaction zone through the outer surface of the first flow guiding module.

[0034] In some embodiments, the flow guiding device is in the shape of an inverted cone, such as a triangular pyramid, a cone, etc., as long as it can gradually gather and guide the sample liquid to flow down to the liquid reaction zone.

[0035] The first flow guiding module is set around the liquid outlet, forming a liquid channel that radiates downward from the liquid outlet. This allows the sample flowing out of the liquid outlet to smoothly enter the liquid reaction zone, reducing splashing to other parts. This ensures both quantitative sample injection and that all samples flow into the liquid reaction zone for collection and detection, thereby improving the accuracy of the detection results.

[0036] The second flow guiding module is located near the air inlet of the second exhaust channel, forming a downward-radiating channel around the air inlet. This effectively prevents splashed liquid from the liquid reaction zone from entering or clogging the air inlet, ensuring smooth exhaust from the liquid reaction zone. This allows the sample liquid to continue to enter the liquid reaction zone smoothly, ensuring quantitative injection and avoiding errors caused by inaccurate sample volume used for detection, which could affect the detection results.

[0037] The third flow guiding module is located at the top of the liquid reaction zone, forming a sloping structure. This allows the liquid remaining at the top of the liquid reaction zone to flow along the sloping surface to the outer surface of the first flow guiding module, and then smoothly flow into the liquid reaction zone along the outer surface of the first flow guiding module. This ensures that the sample liquid can smoothly enter the liquid reaction zone, reducing errors and guaranteeing accurate detection.

[0038] Furthermore, when the quantitative injection device and the reaction tube are combined into one unit, the opening of the sample tube and the inlet of the quantitative injection device can be sealed together, and a closed gas storage area is formed between the upper end of the quantitative injection device and the inner wall of the reaction tube to store the gas discharged from the gas-liquid exchange area.

[0039] The inlet at the top of the quantitative injection device matches the size of the sample tube opening. After the sample tube collects the sample, it is directly inverted on top of the quantitative injection device, so that the opening of the sample tube and the inlet of the quantitative injection device are fitted together and sealed. This allows the sample in the sample tube to enter the sealed environment as soon as it is collected, without needing to be opened, and will not come into contact with aerosols in the external environment.

[0040] The middle and lower parts of the quantitative injection device are tightly fitted to the reaction tube, with only the upper part having a gap between it and the inner wall of the reaction tube. This gap is called the gas storage zone, used to store gas. When the sample liquid entering the quantitative injection device flows downwards, the gas discharged upwards enters the gas storage zone. When the gas pressure in the gas storage zone increases to match the force exerted by gravity on the sample liquid flowing downwards, equilibrium is reached, and the sample liquid can no longer flow in. Therefore, the quantitative injection device can achieve a quantitative discharge volume of sample directly related to the size of the gas storage zone. The larger the sample volume to be quantitatively discharged, the larger the volume of the gas storage zone needs to be designed. The size of the gas storage zone can be designed according to the actual required volume.

[0041] In some embodiments, a filter membrane is provided below the inlet of the quantitative injection device. When the sample liquid in the sample tube enters the quantitative injection device, it will first be filtered through the filter membrane to remove some impurities in the sample liquid.

[0042] On the other hand, this utility model provides a sample detection method, which uses the microfluidic quantitative detection device described above for detection, and includes the following steps:

[0043] (1) Collect the sample using a sample tube;

[0044] (2) Invert the sample tube above the inlet of the quantitative injection device, which is pre-assembled with the reaction tube;

[0045] (3) The sample in the sample tube flows into the quantitative injection device and is quantitatively discharged to the liquid reaction zone at the bottom of the reaction tube;

[0046] (4) The sample reacts with the reagents in the liquid reaction zone to obtain the sample to be tested;

[0047] (5) Test the sample and read the test results.

[0048] In some methods, the reaction described in step (4) is a nucleic acid isothermal amplification, which requires heating equipment to provide the reaction tube with the appropriate temperature required for isothermal amplification (e.g., 30–65°C).

[0049] The detection described in step (5) is to detect the fluorescence in the sample to be tested, and to determine the content of the target nucleic acid in the sample to be tested based on the fluorescence reading.

[0050] The microfluidic quantitative detection device provided by this utility model has the following beneficial effects:

[0051] 1. By setting up a quantitative injection device, the sample liquid can be automatically and quantitatively transferred into the reaction tube in a closed environment, effectively avoiding the contamination of the sample by aerosols in the environment;

[0052] 2. By setting up a gas-liquid exchange zone in the quantitative injection device, the sample liquid can undergo sufficient gas-liquid exchange during the quantitative transfer process, thereby improving the control accuracy of the gas-liquid exchange volume and thus improving the accuracy of quantitative sample transfer in a closed environment.

[0053] 3. The gas-liquid exchange tank has a large opening, with the bottom edge extending all the way to the liquid surface where the liquid outlet is located. This ensures that all sample liquids can complete sufficient gas-liquid exchange within the gas-liquid exchange tank before flowing out of the liquid outlet. Moreover, this design allows for a larger volume of the gas-liquid exchange tank, making it easier for the sample liquids to undergo gas-liquid exchange and improving the accuracy of quantification.

[0054] 4. Exhaust channels are set in both the gas-liquid exchange tank and the liquid reaction zone to ensure that the sample liquid can get sufficient gas-liquid exchange before flowing out of the liquid outlet and after being quantitatively discharged into the reaction tube, so as to avoid affecting the accuracy of quantification due to insufficient local gas-liquid exchange.

[0055] 5. A flow guide device is installed at the bottom of the quantitative injection device to help guide all sample liquids smoothly to the liquid reaction zone, reduce errors, and ensure accurate detection;

[0056] 6. It has a simple structure, small size, and convenient operation, which can meet the needs of rapid testing anytime, anywhere, and is suitable for more simple testing environments. Attached Figure Description

[0057] Figure 1 This is a schematic diagram of the overall structure of the microfluidic quantitative detection device in Example 1;

[0058] Figure 2 This is an exploded view of the microfluidic quantitative detection device in Example 1;

[0059] Figure 3 This is a cross-sectional view of the microfluidic quantitative detection device in Example 1;

[0060] Figure 4 This is a schematic diagram of the quantitative injection device in Example 1;

[0061] Figure 5 This is a rear view of the quantitative injection device in Example 1;

[0062] Figure 6 This is a side view of the quantitative injection device in Example 1;

[0063] Figure 7 This is a schematic diagram of the flow guiding device structure of the quantitative injection device in Example 1;

[0064] Figure 8 This is a schematic diagram of the sample tube structure in Example 1;

[0065] Figure 9 This is a schematic diagram of the reaction tube structure in Example 1.

[0066] Detailed description

[0067] Detection

[0068] A test indicates the identification or detection of the presence of a substance or material. This substance or material includes, but is not limited to, chemical substances, organic compounds, inorganic compounds, metabolites, drugs or drug metabolites, organic tissues or their metabolites, nucleic acids, proteins, or polymers. Additionally, a test can indicate the quantity of the substance or material being tested. Laboratory tests also include immunoassays, chemical tests, enzyme tests, etc.

[0069] sample

[0070] In this invention, the samples used in the detection device include biological liquids. The initial state of the sample can be liquid, solid, or semi-solid. Solid or semi-solid samples can be converted into liquid samples by any suitable method, such as mixing, crushing, softening, incubating, dissolving, enzymatic hydrolysis, etc., and then poured into the collection chamber. The sample is then detected by the testing element to determine whether it contains the analyte. Samples can be taken from the human body, animals, plants, nature, etc. Samples taken from the human body include, for example, liquid samples such as blood, serum, urine, cerebrospinal fluid, sweat, lymph, saliva, and gastric juice; and solid or semi-solid samples such as feces, hair, keratin, dental plaque, and fingernails / toenails. Samples taken from plants include, for example, solid samples such as roots, stems, and leaves; and liquid or semi-solid samples such as tissue fluid and cell sap prepared from roots, stems, and leaves. Samples taken from nature include, for example, liquid samples such as rainwater, river water, seawater, and groundwater; and solid or semi-solid samples such as soil, rocks, ores, and petroleum.

[0071] In some embodiments, the sample described in this invention is taken from a living organism, such as saliva, which makes self-sampling and testing more convenient.

[0072] Test device

[0073] A testing device typically includes a testing element, which is a component capable of detecting the analyte in a sample. The detection of the analyte by the testing element can be based on any technical principle, such as immunology, chemistry, electricity, optics, molecular biology, or physics. The testing element of this invention can be one type or a combination of two or more testing elements. The testing element has a detection area for displaying the detection results; after the detection is performed, the detection area displays the results.

[0074] Various testing elements can be combined and used in this invention. These include test strips, pretreatment components, and detection components. Testing elements used to analyze analytes (such as drugs or metabolites indicating physical condition) in samples can take various forms, such as immunoassays or chemical analyses. In the detection component, if the analyte is present, it binds to the detection reagent and will be detected. For example, in nucleic acid detection, by labeling a probe with a fluorescent substance, when the target nucleic acid is present in the sample, the probe binds to the target nucleic acid, emitting fluorescence, which can then be detected by a fluorescence detection device. The amount of target nucleic acid is quantitatively detected by the amount of fluorescence.

[0075] like Figures 1-3The microfluidic quantitative detection device 1 provided by this utility model includes a sample tube 2, a quantitative injection device 3, a reaction tube 4, and a swab 5. The sample tube 2 is used to collect samples, and the samples in the sample tube 2 can be quantitatively transferred to the reaction tube 4 through the quantitative injection device 3. The swab 5 is used to collect various biological samples such as saliva, sweat, and blood. The reaction tube 4 is used to receive the sample liquid quantitatively transferred by the quantitative injection device 3, process the sample liquid, and then use it for detection. The microfluidic quantitative detection device 1 is suitable for the detection of various analytes and can be used to quantitatively transfer sample liquid to the reaction tube 4 for pretreatment in a closed state before detection.

[0076] In some embodiments, the microfluidic quantitative detection device 1 is used for the detection of target nucleic acids. The sample tube 2 contains pre-treated reagents, including diluents, lysis buffers, etc., which can be used to extract the sample solution to be tested from the swab 5. The sample solution contains nucleic acids. At the start of sampling, the swab 5 is first removed to collect the sample. Then, the swab 5 containing the sample is inserted into the pre-treated solution in the sample tube 2. The sample in the swab 5 enters the pre-treated solution, forming the sample solution.

[0077] In some methods, reaction tube 4 needs to pre-contain amplification reagents, including but not limited to ERA, RPA, LAMP, NEAR, NASBA, HAD, TMA, SAT, RCR, etc., which can be in liquid or solid form. Solid form preparations include but are not limited to spherical, powdered, tablet, or block-shaped preparations obtained by lyophilization, drying, or air drying. The probes of the amplification reagents are also attached with fluorescent markers to indicate the quantity of target nucleic acids in the sample solution. After a quantitative amount of sample solution flows into the liquid reaction zone, it can be mixed with the amplification reagents and undergo an amplification reaction for nucleic acid detection.

[0078] To detect the target nucleic acid in the sample solution, the sample solution in sample tube 2 needs to be quantitatively transferred to reaction tube 4 for nucleic acid amplification, thus enabling nucleic acid detection. Quantitative transfer here refers to transferring a specific volume of sample solution into reaction tube 4. Inaccurate quantification, resulting in too much or too little sample solution entering reaction tube 4, will directly lead to inaccurate detection results. The quantitative transfer process must be completed in a sealed environment. Therefore, with the assistance of the quantitative injection device 3, the sample is quantitatively transferred from sample tube 2 to reaction tube 4. When sample tube 2, quantitative injection device 3, and reaction tube 4 are combined into one unit, the entire device is sealed, thus preventing the sample solution from being affected by aerosols in the external environment and preventing the spillage of infectious viruses contained in the sample solution, which could cause infection to personnel.

[0079] Sample tube

[0080] The sample tube 2 is a container for collecting samples. It can be any shape, such as cylindrical, frustum, or polygonal prism, as long as the shape and size of its opening 6 match the inlet 7 of the quantitative injection device 3, so that the sample tube 2 and the quantitative injection device 3 can be sealed together and the sample in the sample tube 2 can flow into the quantitative injection device 3.

[0081] In some configurations, when sample tube 2 is combined with quantitative injection device 3, sample tube 2 is inverted above quantitative injection device 3, and the sample liquid in sample tube 2 can fall directly into quantitative injection device 3 under the action of gravity.

[0082] In some embodiments, the port 6 of the sample tube 2 is provided with a thread that matches the inlet 22 of the quantitative injection device 3, and the port 6 and the inlet 22 are tightened together by screwing the threads to achieve combination and sealing. Alternatively, the port 6 of the sample tube 2 is provided with an external thread, and the inlet 22 of the quantitative injection device 3 is provided with an internal thread, and the port 6 of the sample tube 2 is inserted upside down into the inlet 22 of the quantitative injection device 3 and tightened to achieve combination and sealing.

[0083] In some designs, after the sample tube 2 is inverted, the tube opening 6 can be directly inserted into the quantitative injection device 3 and sealed. A limiting block 11 is provided below the tube opening 6 to limit the depth of the tube opening 6 inserted into the quantitative injection device 3. This design is faster and more convenient.

[0084] In some methods, the sample tube 2 is pre-filled with pretreatment reagents and sealed with aluminum foil before use. When using, the aluminum foil is torn open and the swab 5 after sampling is inserted into the sample tube 2 so that the sample in the swab 5 is extracted into the pretreatment solution.

[0085] In some embodiments, the sample tube 2 may be made of a flexible or elastic material (such as PE), and after being inserted upside down into the inlet 22 of the quantitative injection device 3, the sample liquid in the sample tube 2 may be squeezed to promote the flow of the sample liquid into the quantitative injection device 3.

[0086] swab

[0087] Swab 5 can refer to a small wad of absorbent material wrapped around one end of the handle. The primary purpose of swab 5 is for collecting clinical laboratory specimens. Swab 5 can be packaged separately or as an accessory to sample tube 2.

[0088] reaction tube

[0089] Reaction tube 4 is a hollow, upward-facing tube (e.g., Figure 9The size of the reaction tube 4 needs to match the quantitative injection device 3. The reaction tube 4 can be pre-stored with the reaction reagent and can be pre-assembled and packaged with the quantitative injection device 3. The upper end (the injection port 7 of the quantitative injection device 3) is sealed with aluminum foil.

[0090] like Figures 1-3 The overall size of the reaction tube 4 needs to match the quantitative injection device 3. When the quantitative injection device 3 and the reaction tube 4 are combined, the lower end of the quantitative injection device 3 is in close contact with the tube wall of the reaction tube 4, and the lower end of the quantitative injection device 3 cannot be in direct contact with the bottom of the reaction tube 4. There is a liquid reaction zone 8. After the sample passes through the quantitative injection device 3, it is quantitatively discharged into the liquid reaction zone 5.

[0091] In some embodiments, the quantitative injection device 3 and the reaction tube 4 can be combined in such a way that the quantitative injection device 3 is inserted into the reaction tube 4, or the reaction tube 4 is inserted below the quantitative injection device 3.

[0092] In some embodiments, the outer edge of the inlet 22 of the quantitative injection device 3 is provided with a track 9, and the upper end 10 of the reaction tube 4 can be inserted into the track 9 to achieve a sealed assembly. Therefore, after the quantitative injection device 3 and the reaction tube 4 are combined, the entire assembly can be sealed by simply sealing the inlet 7 of the quantitative injection device 3 with aluminum foil.

[0093] In some methods, the amplification reagent is pre-stored in the reaction tube 4 and placed in the liquid reaction zone 8. The volume of the amplification reagent is smaller than that of the liquid reaction zone 8. Moreover, when the sample solution enters the liquid reaction zone 8, the volume of the mixture after the sample solution and the amplification reagent are mixed is still smaller than that of the liquid reaction zone.

[0094] It is understandable that after the reaction tube 4 and the quantitative injection device 3 are combined, the combination method includes two types: tight fit and gap. The tight fit part includes the location of the gas-liquid exchange tank 17 in the quantitative injection device 3 and at least part of the first exhaust channel 12 connected to the gas-liquid exchange tank 17. The gap part includes the upper end of the quantitative injection device 3. This gap makes the outer wall 13 of the injection device 3 and the inner wall 14 of the reaction tube 4 form a gas storage area 15, which is used to store and contain the gas generated by gas-liquid exchange and the gas in the original space.

[0095] Quantitative injection device

[0096] The quantitative injection device 3 is the most critical component within the microfluidic quantitative detection device 1 (detection device 1) that enables the quantitative discharge of sample liquid. The quantitative injection device 3 is equipped with a gas-liquid exchange zone 16. This zone 16 facilitates gas-liquid exchange within the quantitative injection device 3, thereby transferring the sample from the device to the reaction tube 4. The quantitative injection device 3 limits the amount of liquid transferred to the reaction tube 4 by controlling the amount of gas used for gas-liquid exchange in the gas-liquid exchange zone 16. In other words, the quantitative injection device 3 primarily achieves quantitative transfer of sample liquid in a closed environment through the gas-liquid exchange zone 16.

[0097] The principle of quantitative injection device 3 provided by this utility model is as follows: the sample liquid flows into the quantitative injection device 3 under the action of gravity, and needs to overcome a certain air pressure to discharge a certain volume of gas into the closed space (such as the gas-liquid exchange zone 16). The gas in the closed space is compressed. When the pressure of the compressed gas and the force that the liquid can overcome the air pressure to enter the reaction tube 4 reach equilibrium, that is, the gravity of the sample liquid is the same as the air pressure, the sample liquid can no longer flow into the reaction tube 4. Since the gravity of the sample liquid is basically the same, the amount of liquid entering the reaction tube 4 through the quantitative injection device 3 each time is also fixed.

[0098] When the sample solution in sample tube 2 flows from sample tube 2 into reaction tube 4 through quantitative injection device 3, since the detection device 1 is closed, the sample solution needs to complete gas-liquid exchange in gas-liquid exchange zone 16. That is, during the downward flow of liquid, gas needs to be expelled upward so that the sample solution can flow smoothly into reaction tube 4. The more sample solution that can complete gas-liquid exchange, the more sample solution flows into reaction tube 4. At the same time, since the detection device 1 is closed, the space used for gas storage is fixed, so the amount of gas available for gas-liquid exchange is also fixed, and the volume of sample solution that can flow into reaction tube 4 is also fixed. Even if the volume of sample solution in sample tube 2 increases, the amount of sample solution that can flow into reaction tube 4 remains constant, and the remaining sample solution cannot flow into reaction tube 4. This ensures that the amount of sample amplified in the sample solution is fixed, thus ensuring the accuracy of the target nucleic acid detection results in the sample solution.

[0099] like Figures 4-7The gas-liquid exchange zone 16 includes a gas-liquid exchange tank 17, the opening 18 of which is located at the side opening 19 of the quantitative injection device 3. When the quantitative injection device 3 and the reaction tube 4 are integrated, the opening 18 is sealed by the inner wall 20 of the reaction tube 4. The gas-liquid exchange zone 16 also includes a first exhaust channel 12, the inlet 7 of which is in gas communication with the gas-liquid exchange tank 17. The gas-liquid exchange tank 17 is designed to ensure sufficient gas-liquid exchange during the process of sample liquid flowing into the quantitative injection device 3 and before it flows out. The opening 18 of the gas-liquid exchange tank 17 is longitudinally opened along the side wall of the quantitative injection device 3, and the length of the longitudinal opening is relatively long, so that the entire process before the sample flows out of the quantitative injection device 3 is almost entirely within the gas-liquid exchange tank 17 for gas-liquid exchange. The more sufficient the gas-liquid exchange, the more accurate the quantitative effect of controlling the sample liquid through gas-liquid exchange.

[0100] When the quantitative injection device 3 and the reaction tube 4 are combined into one unit, although the inlet is sealed by the inner wall 20 of the reaction tube 4, the sample liquid entering the gas-liquid exchange tank 17 can still achieve sufficient gas-liquid exchange due to the first exhaust channel 12 connecting to the gas-liquid exchange tank 17. The first exhaust channel 12 starts from the gas-liquid exchange tank 17 and extends upward along the outer wall of the quantitative injection device 3. When the sample liquid is injected, excess gas in the gas-liquid exchange tank 17 needs to be discharged. Since the outer wall of the quantitative injection device 3 at this part is tightly attached to the inner wall of the reaction tube 4, the gas can only be discharged upward along the channel formed between the groove 21 of the first exhaust channel 12 and the inner wall 20 of the reaction tube 4. Moreover, this channel (the first exhaust channel 12) is curved and meanders upward, which provides more buffering for the exhaust process, avoids sudden large-volume rapid exhaust from affecting the accuracy of quantification, and improves the precision of quantitative injection.

[0101] The quantitative injection device 3 also includes an inlet 22 and an outlet 23. The inlet 22 is sized to match the opening 6 of the sample tube 2. The sample enters the quantitative injection device 3 through the inlet 22 and is then quantitatively discharged into the reaction tube 4 through the outlet 23. During normal use, the quantitative injection device 3 is vertically inserted into the reaction tube 4. The upper end 24 of the quantitative injection device 3 has the inlet 22, and the lower end 25 has the outlet 23 on its bottom surface 26. The outlet 23 is a small orifice. After the sample liquid is quantitatively discharged from the outlet 23 into the reaction tube 4, some excess sample liquid may remain above the outlet 23, inside the quantitative injection device 3. To prevent excess sample liquid from communicating with the liquid in the reaction tube 4 through the outlet 23, which could affect the sample below the outlet 23 and thus the detection results, the sample liquid size needs to be set as small as possible, just enough to allow the liquid to flow out. Excess sample liquid can remain in the quantitative injection device 3. Because the plane of the liquid outlet 23 is relatively large, while the liquid outlet 23 is relatively small, the excess sample liquid basically cannot enter the liquid outlet 23, and will not affect the sample detection process in the reaction tube 4, thus ensuring the accuracy of the detection results.

[0102] It is understandable that the size of the opening 18 of the gas-liquid exchange tank 17 can be designed as needed, but at least the size of the opening 18 must be larger than the air inlet 7 of the first exhaust channel 12. The larger the opening 18, the more complete the gas-liquid exchange. Therefore, the size of the opening 18 can be set according to the required quantitative sample liquid volume. A larger opening 18 is more suitable for quantitatively quantifying more sample liquid.

[0103] like Figure 4 The opening 18 of the gas-liquid exchange tank 17 extends all the way to the plane where the liquid outlet 23 is located, and the bottom edge 27 of the opening 18 of the gas-liquid exchange tank 17 is flush with the plane where the liquid outlet 23 is located. Therefore, all the sample liquid in the quantitative injection device 3 can complete sufficient gas-liquid exchange in the gas-liquid exchange tank 17 before flowing out of the liquid outlet 23. Moreover, this design makes the volume of the gas-liquid exchange tank 17 larger, making it easier for the incoming sample liquid to undergo gas-liquid exchange and improving the accuracy of quantification.

[0104] In some configurations, when the quantitative injection device 3 and the reaction tube 4 are integrated, a liquid reaction zone 8 is left at the bottom of the reaction tube 4. After the sample is quantitatively discharged through the quantitative injection device 3, it enters the liquid reaction zone 8. When the quantitative injection device 3 and the reaction tube 4 are integrated, the quantitative injection device 3 cannot extend into the bottom of the reaction tube 4. Therefore, a portion of space is left at the bottom of the reaction tube 4 for quantitatively storing the sample to be reacted and detected. This portion of space is the liquid reaction zone 8.

[0105] In some configurations, the gas-liquid exchange zone 16 also includes a second exhaust channel 28, the inlet 29 of which is in gas communication with the liquid reaction zone 8. Since the liquid reaction zone 8 is in a closed state, when the sample liquid enters the liquid reaction zone 8 through the outlet 23, corresponding gas also needs to be discharged; therefore, the liquid reaction zone 8 requires a second exhaust channel 28. The inlet 29 of the second exhaust channel 28 is located at the bottom 30 of the quantitative injection device, below which is the liquid reaction zone 8. Therefore, the second exhaust channel 28 can directly communicate with the gas in the liquid reaction zone 8, and then forms an upward-extending groove along the outer wall of the quantitative injection device 3. Since the quantitative injection device 3 is tightly fitted to the reaction tube 4 at this position, a channel is formed between the groove of the second exhaust channel 28 and the inner wall of the reaction tube 4, allowing gas to be discharged upwards along the channel. This channel is curved and meandering upwards, providing more buffering during the exhaust process and preventing sudden, large-volume, rapid exhaust from affecting the accuracy of the quantitative injection.

[0106] In some configurations, the quantitative injection device 3 is equipped with a flow guide 31 at its lower end to guide the liquid discharged from the outlet 23 to the liquid reaction zone 8. The liquid reaction zone 8 is pre-filled with reaction reagents for sample detection. Because the outlet 23 of the quantitative injection device 3 is relatively small, sample liquid can easily remain in or around the outlet 23. The flow guide 31 helps to quickly guide the retained sample liquid into the liquid reaction zone 8. During the process of entering the liquid reaction zone 8, the sample liquid may splash and remain on the top 32 of the liquid reaction zone 8, or it may splash and remain at the air inlet 29 of the second exhaust channel 28, causing the air inlet 29 to become blocked, thus affecting the accuracy of quantitative injection. Therefore, by setting up the flow guide 31, the sample liquid retained near the outlet 23, near the air inlet 29 of the second exhaust channel 28, and on the top 32 of the liquid reaction zone 8 can be smoothly guided to the liquid reaction zone 8, significantly improving the accuracy of quantitative injection by the quantitative injection device 3.

[0107] In some embodiments, the liquid reaction zone 8 may pre-store amplification reagents for amplifying the target nucleic acid. These reagents include, but are not limited to, amplification reagents for ERA, RPA, LAMP, NEAR, NASBA, HAD, TMA, SAT, RCR, etc., and may be in liquid or solid form. Solid forms include, but are not limited to, spherical, powdered, sheet-like, or block-like forms obtained through lyophilization, drying, air-drying, or crystallization. The probes of the amplification reagents are also attached with fluorescent markers to indicate the quantity of target nucleic acid in the sample solution. After a quantitative amount of sample solution flows into the liquid reaction zone 8, it can be mixed with the amplification reagents and undergo an amplification reaction for nucleic acid detection.

[0108] In some embodiments, the flow guiding device 31 is in the shape of an inverted cone, such as a triangular pyramid, a cone, etc., as long as it can gradually gather and guide the sample liquid to flow down to the liquid reaction zone 8.

[0109] like Figure 7 The flow guiding device 31 includes a first flow guiding module 33, a second flow guiding module 34, and a third flow guiding module 35. The first flow guiding module 33 is provided with a first flow guiding channel 36 for guiding the sample flowing out of the liquid outlet 23 to the liquid reaction zone 8. The second flow guiding module 34 is used to guide the sample splashed out of the liquid reaction zone 8 back to the liquid reaction zone 8. The third flow guiding module 35 is used to guide the sample splashed out of the liquid reaction zone 8 to the outer surface 38 of the first flow guiding module 33, and then guide it to the liquid reaction zone 8 through the outer surface 38 of the first flow guiding module.

[0110] In some embodiments, the first flow guiding module 33 is arranged around the liquid outlet 23 to form a liquid channel (first flow guiding channel 36) that radiates downward from the liquid outlet 23, so that the sample flowing out of the liquid outlet 23 can smoothly enter the liquid reaction zone 8, reducing the splashing to other parts, ensuring both quantitative sample injection and ensuring that the sample flows into the liquid reaction zone 8 and is collected for detection, thereby improving the accuracy of the detection results.

[0111] The second flow guiding module 34 is located near the air inlet 29 of the second exhaust channel 28, forming a downward-radiating channel around the air inlet 29. This effectively prevents the liquid splashed from the liquid reaction zone 8 from entering the air inlet 29 or blocking the air inlet 29, ensuring that the liquid reaction zone 8 can exhaust smoothly. This allows the sample liquid to continue to enter the liquid reaction zone 8 smoothly, ensuring quantitative injection and avoiding errors caused by inaccurate sample volume used for detection, which could affect the detection results.

[0112] The third flow guiding module 35 is set at the top 32 of the liquid reaction zone 8, forming a sloping structure 37. This allows the liquid retained at the top 32 of the liquid reaction zone to flow along the sloping structure 37 to the outer surface 38 of the first flow guiding module 33, and then smoothly flow into the liquid reaction zone 8 along the outer surface 38 of the first flow guiding module 33. This ensures that the sample liquid can smoothly enter the liquid reaction zone 8, reducing errors and ensuring accurate detection.

[0113] When the quantitative injection device 3 and the reaction tube 4 are combined into one unit, the port 6 of the sample tube 2 is combined with the inlet of the quantitative injection device to achieve a seal. A closed gas storage area 15 is formed between the upper end 24 of the quantitative injection device 3 and the inner wall 14 of the reaction tube 4 to store the gas discharged from the gas-liquid exchange area 15.

[0114] The inlet 7 of the upper end 24 of the quantitative injection device 3 is matched with the inlet 6 of the sample tube 2. When the sample tube 2 collects the sample, it is directly inverted on top of the quantitative injection device 3, so that the inlet 6 of the sample tube 2 and the inlet 7 of the quantitative injection device 3 are fitted together and sealed. This allows the sample in the sample tube 2 to enter the sealed environment as soon as it is collected, without needing to be opened, and will not come into contact with aerosols in the external environment.

[0115] The middle part 39 and the lower part 25 of the quantitative injection device 3 are tightly fitted to the reaction tube 4. Only the upper part 24 has a gap between it and the inner wall 14 of the reaction tube 4. This gap is called the gas storage area 15, which is used to store gas. When the sample liquid entering the quantitative injection device 3 flows downward, the gas discharged upward will enter the gas storage area 15. When the gas pressure in the gas storage area 15 increases to the same magnitude as the force of the sample liquid flowing downward under gravity, equilibrium is reached, and the sample liquid can no longer flow in. Therefore, the sample volume that the quantitative injection device 3 can quantitatively discharge is directly related to the size of the gas storage area 15. The larger the sample volume to be quantitatively discharged, the larger the volume of the gas storage area 15 needs to be designed. The size of the gas storage area 15 can be designed according to the actual required volume.

[0116] like Figure 6 Preferably, a filter membrane 40 can be installed below the injection port 7 of the quantitative injection device 3. When the sample liquid in the sample tube 2 enters the quantitative injection device 3, it will first be filtered by the filter membrane 40 to remove some impurities in the sample liquid. Of course, if the sample liquid itself is relatively clean, it is not necessary to install the filter membrane 40. Detailed Implementation

[0117] The preferred embodiments of this utility model will be described in further detail below with reference to the accompanying drawings. It should be noted that the embodiments described below are intended to facilitate understanding of this utility model and are not intended to limit it in any way. The raw materials and equipment used in the specific embodiments of this utility model are all known products and were obtained by purchasing commercially available products.

[0118] In the description of this utility model, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0119] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0120] Example 1: Microfluidic quantitative detection device provided by this utility model

[0121] The structure of the microfluidic quantitative detection device provided in this embodiment is as follows: Figures 1-9 As shown, where Figure 1 This is a schematic diagram of the overall structure of a microfluidic quantitative detection device. Figure 2 An exploded view of a microfluidic quantitative detection device; Figure 3 This is a cross-sectional view of a microfluidic quantitative detection device; Figure 4 This is a schematic diagram of the quantitative injection device. Figure 5 This is a rear view of the quantitative injection device; Figure 6 This is a side view of the quantitative injection device; Figure 7 This is a schematic diagram of the flow guiding device for a quantitative sample injection apparatus. Figure 8 This is a schematic diagram of the sample tube structure; Figure 9 This is a schematic diagram of the reaction tube structure.

[0122] like Figures 1-3As shown, the microfluidic quantitative detection device 1 provided in this embodiment includes a sample tube 2, a quantitative injection device 3, and a reaction tube 4. It also includes a sample tube 2, a quantitative injection device 3, a reaction tube 4, and a swab 5. The quantitative injection device 3 and the reaction tube 4 are combined together, and the inlet of the quantitative injection device 3 is sealed with aluminum foil. The sample tube 2 and the swab 5 are used to collect samples. When the sample tube 2, the quantitative injection device 3, and the reaction tube 4 are detachably combined into one unit, a seal can be achieved. At this time, the sample in the sample tube 2 can be quantitatively transferred to the reaction tube 4 through the quantitative injection device 3. When performing nucleic acid detection, the sample tube 2 can be pre-filled with lysis buffer for pre-treatment such as lysis of the sample collected by the sampling swab to extract nucleic acid. At the start of sampling, the swab 5 is first removed to collect the sample, and then the swab 5 containing the sample is inserted into the lysis buffer in the sample tube 6. The sample in the swab 5 enters the lysis buffer, forming a sample solution.

[0123] like Figures 4-7 The quantitative injection device 3 is equipped with a gas-liquid exchange zone 16. This zone 16 facilitates gas-liquid exchange within the device, transferring the sample from the device to the reaction tube 4. The quantitative injection device 3 limits the amount of liquid transferred to the reaction tube 4 by restricting the amount of gas used for gas-liquid exchange in the gas-liquid exchange zone 16. When the sample liquid in the sample tube 2 flows from the sample tube 2 into the reaction tube 4 via the quantitative injection device 3, since the device 1 is closed, the sample liquid needs to pass through the gas-liquid exchange zone 16 to complete the gas-liquid exchange. In other words, as the liquid flows downwards, the gas needs to be expelled upwards so that the sample liquid can flow smoothly into the reaction tube 4. The more sample liquid that can complete the gas-liquid exchange, the more sample liquid flows into the reaction tube 2. Simultaneously, because the device 1 is closed, the space for storing gas is fixed, therefore the amount of gas available for gas-liquid exchange is also limited.

[0124] The gas-liquid exchange zone 16 includes a gas-liquid exchange tank 17, the opening 18 of which is located at the side opening 19 of the quantitative injection device 3. When the quantitative injection device 3 and the reaction tube 4 are integrated, the opening 18 is sealed by the inner wall 20 of the reaction tube 4. The gas-liquid exchange zone 16 also includes a first exhaust channel 12, the inlet 7 of which is in gas communication with the gas-liquid exchange tank 17. The gas-liquid exchange tank 17 is designed to ensure sufficient gas-liquid exchange during the process of sample liquid flowing into the quantitative injection device 3 but before it flows out. The opening 18 of the gas-liquid exchange tank 17 is longitudinally opened along the side wall of the quantitative injection device 3, and the length of the longitudinal opening is relatively long, so that the entire process before the sample flows out of the quantitative injection device 3 is almost entirely within the gas-liquid exchange tank 17 for gas-liquid exchange. The first exhaust channel 12 extends upward from the gas-liquid exchange tank 17 along the outer wall of the quantitative injection device 3. When the sample liquid is injected, the excess gas in the gas-liquid exchange tank 17 needs to be discharged. Since the outer wall of the quantitative injection device 3 is in close contact with the inner wall of the reaction tube 4 at this part, the gas can only be discharged upward along the channel formed between the groove 21 of the first exhaust channel 12 and the inner wall 20 of the reaction tube 4. Moreover, the channel (first exhaust channel 12) is curved and meanders upward, so that the exhaust process has more buffer.

[0125] The quantitative injection device 3 also includes an inlet 22 and an outlet 23. The inlet 22 is sized to match the opening 6 of the sample tube 2, and a limiting block 11 is provided below the opening 6. The sample enters the quantitative injection device 3 through the inlet 22 and is then quantitatively discharged into the reaction tube 4 through the outlet 23. During normal use, the quantitative injection device 3 is inserted vertically into the reaction tube 4. The upper end 24 of the quantitative injection device 3 has the inlet 22, and the lower bottom surface 26 of the lower end 25 has the outlet 23. The outlet 23 is a small hole. The opening 18 of the gas-liquid exchange tank 17 extends to the plane where the outlet 23 is located, and the lower bottom edge 27 of the opening 18 of the gas-liquid exchange tank 17 is flush with the plane where the outlet 23 is located. When the quantitative injection device 3 and the reaction tube 4 are combined into one unit, a liquid reaction zone 8 is left at the bottom of the reaction tube 4. The sample enters the liquid reaction zone 8 after being quantitatively discharged by the quantitative injection device 3. The gas-liquid exchange zone 16 also includes a second exhaust channel 28, whose inlet 29 is connected to the gas in the liquid reaction zone 8. The inlet 29 of the second exhaust channel 28 is located at the bottom 30 of the quantitative injection device, below which is the liquid reaction zone 8. Therefore, the second exhaust channel 28 can directly communicate with the gas in the liquid reaction zone 8, forming an upward-extending groove along the outer wall of the quantitative injection device 3. Since the quantitative injection device 3 is tightly fitted to the reaction tube 4 at this location, a channel is formed between the groove of the second exhaust channel 28 and the inner wall of the reaction tube 4, allowing gas to be discharged upwards along the channel. This channel is curved and meandering upwards, providing more buffering during the exhaust process.

[0126] like Figure 7 The quantitative injection device 3 is equipped with a flow guiding device 31 at its lower end to guide the liquid discharged from the outlet 23 to the liquid reaction zone 8. The liquid reaction zone 8 is pre-filled with reaction reagents for sample detection. Because the outlet 23 of the quantitative injection device 3 is small, the sample liquid is prone to stagnation in the outlet 23 or around the area below it. The flow guiding device 31 helps to guide the stagnant sample liquid to the liquid reaction zone 8 as quickly as possible. During the process of the sample liquid entering the liquid reaction zone 8, it may splash and stagnate at the top 32 of the liquid reaction zone 8 (which is also equivalent to the bottom 30 of the quantitative injection device). It may also splash and stagnate at the air inlet 29 of the second exhaust channel 28, causing the air inlet 29 to be blocked, which will also affect the accuracy of quantitative injection. Therefore, by setting up the flow guiding device 31, the sample liquid near the liquid outlet 23, near the air inlet 29 of the second exhaust channel 28, and at the top 32 of the liquid reaction zone 8 can be smoothly guided to the liquid reaction zone 8, which can significantly improve the accuracy of quantitative injection by the quantitative injection device 3. The liquid reaction zone 8 can be pre-stored with amplification reagents for amplifying target nucleic acids. After a quantitative amount of sample liquid flows into the liquid reaction zone 8, it can be mixed with the amplification reagents and undergo an amplification reaction, thereby being used for nucleic acid detection.

[0127] The flow guiding device 31 is an inverted cone shape, which can be a triangular pyramid, a cone, or other forms, as long as it can gradually gather and guide the sample liquid to flow down to the liquid reaction zone 8. The flow guiding device 31 includes a first flow guiding module 33, a second flow guiding module 34, and a third flow guiding module 35; the first flow guiding module 33 is provided with a first flow guiding channel 36 to guide the sample flowing out of the liquid outlet 23 to the liquid reaction zone 8; the second flow guiding module 34 is used to guide the sample splashed out of the liquid reaction zone 8 back to the liquid reaction zone 8; the third flow guiding module 35 is used to guide the sample splashed out of the liquid reaction zone 8 to the outer surface 38 of the first flow guiding module 33, and then guide it to the liquid reaction zone 8 through the outer surface 38 of the first flow guiding module. The first flow guiding module 33 is positioned around the liquid outlet 23, forming a downward-radiating liquid channel (first flow guiding channel 36) from the liquid outlet 23. This allows the sample flowing out of the liquid outlet 23 to smoothly enter the liquid reaction zone 8, reducing splashing to other parts. This ensures both quantitative sample injection and that all samples flow into the liquid reaction zone 8 for detection, improving the accuracy of the detection results. The second flow guiding module 34 is positioned near the air inlet 29 of the second exhaust channel 28, forming a downward-radiating channel around the air inlet 29. This effectively prevents splashed liquid from the liquid reaction zone 8 from entering or blocking the air inlet 29, ensuring smooth exhaust from the liquid reaction zone 8. This allows the sample liquid to continue to smoothly enter the liquid reaction zone 8, ensuring quantitative sample injection and avoiding errors in the detection results caused by inaccurate sample volume. The third flow guiding module 35 is set at the top 32 of the liquid reaction zone 8, forming a sloping structure 37. This allows the liquid retained at the top 32 of the liquid reaction zone to flow along the sloping structure 37 to the outer surface 38 of the first flow guiding module 33, and then smoothly flow into the liquid reaction zone 8 along the outer surface 38 of the first flow guiding module 33. This ensures that the sample liquid can smoothly enter the liquid reaction zone 8, reducing errors and ensuring accurate detection.

[0128] When the quantitative injection device 3 and the reaction tube 4 are combined into one unit, the port 6 of the sample tube 2 is sealed with the inlet of the quantitative injection device. A closed gas storage area 15 is formed between the upper end 24 of the quantitative injection device 3 and the inner wall 14 of the reaction tube 4 to store the gas discharged from the gas-liquid exchange area 15. The inlet 7 of the upper end 24 of the quantitative injection device 3 matches the size of the port 6 of the sample tube 2. When the sample tube 2 collects a sample, it is directly inverted and placed above the quantitative injection device 3, so that the port 6 of the sample tube 2 and the inlet 7 of the quantitative injection device 3 fit together and seal. This allows the sample in the sample tube 2 to enter the sealed environment immediately upon collection, without needing to be opened, and thus preventing contact with aerosols in the external environment. The middle part 39 and the lower part 25 of the quantitative injection device 3 are tightly fitted to the reaction tube 4, with only the upper part 24 having a gap between it and the inner wall 14 of the reaction tube 4. This gap is called the gas storage area 15, which is used to store gas. The size of the gas storage area 15 can be designed according to the actual required volume. Figure 6Preferably, a filter membrane 40 can be installed below the injection port 7 of the quantitative injection device 3. When the sample liquid in the sample tube 2 enters the quantitative injection device 3, it will first be filtered by the filter membrane 40 to remove some impurities in the sample liquid. Of course, if the sample liquid itself is relatively clean, it is not necessary to install the filter membrane 40.

[0129] The sample detection method using the microfluidic quantitative detection device 1 provided in this embodiment includes the following steps:

[0130] (1) Collect the sample using sample tube 2;

[0131] (2) Invert the sample tube 2 above the inlet of the quantitative injection device 3. The quantitative injection device 3 is pre-assembled with the reaction tube 4.

[0132] (3) The sample in the sample tube 2 flows into the quantitative injection device 3 and is quantitatively discharged to the liquid reaction zone 8 at the bottom of the reaction tube 4;

[0133] (4) The sample reacts with the reaction reagent in the liquid reaction zone 8 to obtain the sample to be tested; the reaction is a nucleic acid isothermal amplification, which requires a heating device to provide the reaction tube 2 with a suitable isothermal amplification temperature (e.g., 30-65℃);

[0134] (5) Detect the fluorescence in the sample to be tested, and determine the content of target nucleic acid in the sample to be tested based on the fluorescence reading.

[0135] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0136] While the present invention has been disclosed above, it is not limited thereto. Its applications in the field of microfluidics can be expanded accordingly. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A microfluidic quantitative detection device, characterized in that, The device comprises a sample tube for collecting sample, a quantitative sample feeding device, and a reaction tube. When the sample tube, the quantitative sample feeding device, and the reaction tube are combined into an integrated whole, the integrated whole can be sealed, and the sample in the sample tube can be quantitatively transferred into the reaction tube through the quantitative sample feeding device. The quantitative sample feeding device is provided with a gas-liquid exchange zone. The quantitative sample feeding device limits the amount of gas used for gas-liquid exchange in the gas-liquid exchange zone, thereby limiting the amount of liquid transferred into the reaction tube by the quantitative sample feeding device.

2. The microfluidic quantitative detection device according to claim 1, wherein, The gas-liquid exchange zone is used to complete gas-liquid exchange in the quantitative sample feeding device, thereby helping the sample to be transferred from the quantitative sample feeding device into the reaction tube.

3. The microfluidic quantitative detection device according to claim 2, wherein, The gas-liquid exchange zone comprises a gas-liquid exchange groove, and the groove opening of the gas-liquid exchange groove is located at the lateral opening of the quantitative sample feeding device. When the quantitative sample feeding device and the reaction tube are combined into an integrated whole, the groove opening is closed by the wall of the reaction tube.

4. The microfluidic quantitative detection device according to claim 3, wherein, The gas-liquid exchange zone further comprises a first gas discharge channel, and the gas inlet of the first gas discharge channel is in gas communication with the gas-liquid exchange groove.

5. The microfluidic quantitative test device of claim 4, wherein, The quantitative sample feeding device further comprises a sample inlet and a liquid outlet hole. The sample inlet is matched in size with the opening of the sample tube. The sample enters the quantitative sample feeding device through the sample inlet and is quantitatively discharged into the reaction tube through the liquid outlet hole.

6. The microfluidic quantitative test device of claim 5, wherein, The lower bottom edge of the groove opening of the gas-liquid exchange groove is flush with the plane where the liquid outlet hole is located.

7. The microfluidic quantitative test device of claim 6, wherein, When the quantitative sample feeding device and the reaction tube are combined into an integrated whole, a liquid reaction zone is left at the bottom of the reaction tube. After the sample is quantitatively discharged by the quantitative sample feeding device, the sample enters the liquid reaction zone. The gas-liquid exchange zone further comprises a second gas discharge channel, and the gas inlet of the second gas discharge channel is in gas communication with the liquid reaction zone.

8. The microfluidic quantitative test device of claim 7, wherein, The lower end of the quantitative sample feeding device is provided with a flow guide device for guiding the liquid discharged from the liquid outlet hole to the liquid reaction zone. The liquid reaction zone is preloaded with a reaction reagent for detecting the sample.

9. The microfluidic quantitative detection device according to claim 8, wherein, The flow guide device comprises a first flow guide module, a second flow guide module, and a third flow guide module. The first flow guide module is provided with a first flow guide channel for guiding the sample discharged from the liquid outlet hole to the liquid reaction zone. The second flow guide module is used for guiding the sample splashed from the liquid reaction zone back to the liquid reaction zone, and the third flow guide module is used for guiding the sample splashed from the liquid reaction zone to the outer surface of the first flow guide module and then guiding the sample to the liquid reaction zone through the outer surface of the first flow guide module.

10. The microfluidic quantitative test device of claim 9, wherein, When the quantitative sample feeding device and the reaction tube are combined into an integrated whole, the opening of the sample tube and the sample inlet of the quantitative sample feeding device can be sealed after being combined, and a closed gas storage zone is formed between the upper end of the quantitative sample feeding device and the inner wall of the reaction tube, which is used for storing the gas discharged from the gas-liquid exchange zone.

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