Centrifugal micro-fluidic chip

Abstract

According to the centrifugal micro-fluidic chip provided by the utility model, one or more concentric sub-chips are arranged outside the chip body, so that high-throughput detection of more samples and more detection items can be realized, and the detection efficiency is improved; the exhaust channel is led out from the fluid channel between the reaction cavity and the detection cavity, the exhaust direction of the exhaust channel is opposite to the rotating centrifugal direction, the exhaust port is connected with the main flow channel and is higher than the fluid channel, and the flow of gas and liquid in the reaction cavity and the detection cavity can be effectively controlled by combining the atmospheric pressure internal and external balance principle and the centrifugal driving performance; the sample quantity entering each chamber can be effectively controlled, multiple detection of nucleic acid can be completed only through two times of centrifugation, the to-be-detected sample can stably remain and react after entering each chamber, the sample backflow is effectively prevented, and the problem of mutual interference or pollution is avoided.

Description

Technical Field

[0001] The utility model relates to the field of microfluidic control, in particular to a centrifugal microfluidic chip. Background Art

[0002] Existing microfluidic chips have integrated multiple steps such as sample processing, nucleic acid amplification, and nucleic acid detection on a small chip, quickly completing the "sample in - result out" detection process. Since microfluidic chips are free from the dependence on precision pipetting devices and professionals, they have great potential in the field of nucleic acid sample detection.

[0003] Isothermal amplification has gained more and more attention in the field of instant testing due to its fast reaction speed and low requirements for instruments and equipment. However, due to the complexity of the samples to be tested, such as blood, sputum, urine, tissue, etc., it is usually necessary to react with the detection reagent to amplify the signal after isothermal amplification to achieve accurate detection, which is called nucleic acid multiplex detection. In order to achieve nucleic acid multiplex detection, a reaction chamber and a detection chamber must be provided in the microfluidic chip at the same time. The reaction chamber is used for amplification reaction, and the detection chamber is used for signal amplification. The sample to be tested needs to be transferred in a controllable manner between the reaction chamber and the detection chamber, and the cross-effect caused by sample reflux can be prevented.

[0004] Centrifugal microfluidic chips drive the flow of liquid by rotating the centrifugal microfluidic chip, which can use centrifugal force to manipulate liquid on a submillimeter scale. Compared with traditional microfluidic chips, the entire device is more compact and simple to handle, so it is gradually being used in the diagnosis field. In the centrifugal microfluidic chip, the microchannels are distributed along the radial direction of the disk. When the chip rotates, the liquid to be tested moves along multiple microchannels to each reaction pool under the action of centrifugal force, realizing the distribution and addition of the liquid to be tested.

[0005] At present, diagnostic technology usually requires multiple indicators to jointly determine whether a patient has a certain disease. For example, during clinical examinations, the same patient sample needs to be screened for multiple respiratory pathogens, and the above indicators vary according to individual conditions. However, high-throughput centrifugal microfluidic chips also have problems such as short and inaccurate control processes and complex structures. When detecting multiple indicators at the same time, the chambers in the centrifugal microfluidic chip are prone to uneven injection volumes, and may enter other chambers during the centrifugation process, or reflux after the centrifugation is completed, resulting in mutual interference and contamination. As a result, the existing centrifugal microfluidic chips can only perform simultaneous amplification of a single sample or a few detection indicators. For example, the nucleic acid multiple detection microfluidic chip provided by the patent with publication number CN220166182U has a low detection throughput and is difficult to complete the sample and multiple-indicator pathogen screening work in a short time. When faced with the amplification requirements of multiple samples and multiple indicators, it not only cannot provide efficient and rapid amplification work, but also faces high chip replacement costs.

[0006] CN115684014A provides a microfluidic chip for centrifugation. Although it can also achieve high-throughput detection of multiple indicators, the structure and operation process are relatively complicated. Ventilation holes are set on the bottom plate and the cover plate for ventilation of the entire chip. The sample enters the corresponding chamber through centrifugation. Since it is difficult to control the amount of sample entering the chamber each time through centrifugation, a transition pool needs to be set, and the sample volume is measured by the volume of the transition pool. Therefore, it needs to be centrifuged three times to make the liquid reach the target position for detection (the first stage centrifugation reaches the transition pool, the second stage centrifugation reaches the reaction chamber, and the third stage centrifugation reaches the detection chamber). Since the centrifugal speed of the latter stage needs to be significantly higher than that of the previous stage, the liquid can enter the next chamber. Therefore, the three-stage centrifugation will inevitably require higher centrifugal force centrifugation, which is not only more complicated to operate, but also the pre-embedded freeze-dried or vitrified reagents in the chamber are easily precipitated by high-speed centrifugation when the solution is not sufficient, resulting in reaction failure and serious impact on the detection results. At the same time, there are many holes in the chip, and the flow channel and the hole are very small, which makes it difficult to control the work error, resulting in the liquid being easily misplaced and out of control when adding samples.

[0007] Therefore, there is an urgent need to find a method with a simple structure that can accurately allow samples to enter the corresponding chambers with fewer centrifugation times, and can effectively control the amount of samples entering each chamber without the problem of sample backflow or leakage to other chambers, completely solving the problems of mutual interference and contamination, and can perform high-throughput testing of multiple samples and multiple test items, and ensure the accuracy of the test results. Utility Model Content

[0008] In order to solve the above problems, the utility model provides a centrifugal microfluidic chip, in which one or more concentric circle sub-chips are arranged outside the chip body, which can realize high-throughput detection of more samples and more detection items and improve detection efficiency; an exhaust channel is led out on the fluid channel between the reaction chamber and the detection chamber, and the exhaust direction of the exhaust channel is opposite to the rotating centrifugal direction, the exhaust port is connected to the main channel, and the position is higher than the fluid channel, combined with the principle of internal and external balance of atmospheric pressure and centrifugal driving performance, it can effectively control the flow of gas and liquid in the reaction chamber and the detection chamber, and can effectively control the amount of samples entering each chamber, and can complete multiple nucleic acid detection with only two centrifugations. After entering each chamber, the sample to be tested can be stably retained and reacted, effectively preventing sample reflux, and eliminating mutual interference or contamination.

[0009] On the one hand, the utility model provides a centrifugal microfluidic chip, including a chip body with a rotation center and one or more sub-chips, wherein the sub-chip is a concentric ring chip located outside the chip body, and the rotation center is used to connect to a centrifugal drive device to drive the centrifugal microfluidic chip to centrifuge; the chip body and the sub-chip are both provided with a reaction chamber for sample nucleic acid amplification and a detection chamber for sample detection.

[0010] The centrifugal microfluidic chip provided by the utility model decomposes a traditional single centrifugal microfluidic chip into a chip body and a sub-chip. The chip body and the sub-chip operate independently and are compact and easy to operate. They can perform multi-index detection of multiple samples at the same time, greatly improving the detection efficiency and meeting the needs of fast, convenient, low-cost high-throughput diagnosis. It has important application value in the field of clinical diagnosis or rapid on-site screening.

[0011] The chip body and the sub-chip can be directly molded and manufactured in one chip and directly connected into one body, or they can be manufactured separately and fixed for use by means of snap-fit ​​connection or the like.

[0012] In some methods, the sub-chip, the chip body and the entire microfluidic chip are all in the same plane. The sub-chip is located outside the chip body and has a larger diameter, so more groups of detection units can be set up. At the same time, the sub-chip can also be provided with a sample loading port and a waste liquid pool to independently perform multiple nucleic acid detections. It can detect samples different from the chip body, realize simultaneous detection of multiple samples, and can detect more indicators at the same time (each detection unit can detect a nucleic acid target), significantly increasing the detection throughput and improving the detection efficiency.

[0013] In some methods, the number of sub-chips and the number of detection units in each sub-chip or the chip itself can be flexibly set according to the number of samples to be tested and the index detection requirements, and the reaction chamber of each detection unit and the solid reagent built into the detection chamber can be flexibly set according to actual needs. For example, amplification primers for different respiratory targets can be built into different reaction chambers, and corresponding detection reagents can be built into corresponding detection chambers, so that multiple detection of respiratory pathogens can be flexibly achieved.

[0014] In some embodiments, the centrifugal microfluidic chip includes a chip body and a sub-chip.

[0015] The chip body of the centrifugal microfluidic chip is provided with multiple groups of detection units, each group of detection units is provided with a reaction chamber and a detection chamber, which can be applied to the simultaneous detection of multiple different target analytes, such as the detection of multiple different nucleic acid targets, and each group of detection units can realize multiple nucleic acid detection. Of course, it can be understood that the centrifugal microfluidic chip of the present application is not only applicable to multiple nucleic acid detection, but also applicable to other types of molecular detection such as protein and antibody, the reaction chamber can be used for sample nucleic acid amplification, and the detection chamber is used for sample detection.

[0016] During use, the centrifugal microfluidic chip needs to be kept horizontal with the sample port facing upward. In some ways, the centrifugal microfluidic chip can be inserted into a matching detection device, so that the centrifugal microfluidic chip is kept horizontally placed with the sample port facing upward, and the rotation center is buckled and fixed with the rotating shaft of the detection device for centrifugation, so that the rotating shaft can drive the centrifugal microfluidic chip to rotate centrifugally; in some ways, the detection device can provide a heat source for the reaction chamber of the centrifugal microfluidic chip to heat it; in some ways, the detection device can also detect the fluorescent substance produced after the sample reaction in the centrifugal microfluidic chip and read the detection result.

[0017] Furthermore, the reaction chamber and the detection chamber are connected via a fluid channel, and an exhaust channel is also provided on the fluid channel, and the exhaust channel is used to control the flow of gas in the reaction chamber or the detection chamber.

[0018] Since centrifugal microfluidic chips need to control the flow of liquid through centrifugation, exhaust channels cannot be set for each reaction chamber and detection chamber. This is because when each chamber is equipped with an exhaust channel, it is difficult to control the flow of samples during the centrifugation process. The sample may directly pass through the reaction chamber to the detection chamber under the action of centrifugation, affecting the amplification and detection results. Therefore, existing centrifugal microfluidic chips usually only have air holes on the chip floor or cover. Such a setting is not suitable for nucleic acid multiple detection chips because multiple chambers need to be set up. It is difficult to exhaust the rear chamber during the centrifugation process. A larger centrifugal force is required to push the sample in. High-speed centrifugation can easily cause the freeze-dried reagents pre-placed in each chamber to be insufficiently dissolved and precipitate, which seriously affects the accuracy of the test results.

[0019] The centrifugal microfluidic chip provided by the utility model is provided with an exhaust channel on the fluid channel connected between the reaction chamber and the detection chamber in each detection unit, so that the reaction chamber and the detection chamber share one exhaust channel, and the structure of the exhaust channel is improved, and combined with the performance of centrifugation, the reaction chamber and the detection chamber can be smoothly exhausted when they need to be exhausted, and can be smoothly closed to prevent interference when they need to be closed for reaction, and the amount of samples entering the reaction chamber and the detection chamber can be effectively controlled. Multiple nucleic acid tests can be completed by one or two centrifugations, and the problem of leakage or sample reflux can be perfectly avoided. After the samples to be tested enter the corresponding chamber, they can be stably retained in the chamber without reflux and flowing to other chambers, thereby ensuring that each step of the reaction can be completed smoothly, providing guarantee for the accurate detection of the centrifugal microfluidic chip.

[0020] The fluid channel connecting the reaction chamber and the detection chamber refers to a channel connecting the outlet of the reaction chamber and the inlet of the detection chamber.

[0021] Furthermore, the exhaust channel includes an inlet and an outlet, the inlet is the connection between the fluid channel and the exhaust channel, and the outlet is the other end of the exhaust channel; the outlet is closer to the rotation center than the inlet, so that the exhaust direction of the exhaust channel is opposite to or at least partially opposite to the centrifugal direction of rotation.

[0022] When the centrifugal microfluidic chip is centrifuged, the flow direction of the fluid sample under the centrifugal action is emitted from the center of the circle to the outside. In the centrifugal microfluidic chip provided by the utility model, the exhaust channel is led out from the fluid channel between the reaction chamber and the detection chamber, and then approaches the rotation center, so that the exhaust direction is opposite to the centrifugal direction. The fluid sample will not enter the exhaust channel during centrifugation, but will accurately enter the corresponding chamber along the centrifugal direction.

[0023] In some embodiments, the exhaust channel is led out from the middle of the fluid channel or toward a position close to the detection chamber, and the initial section of the leading-out section is an arc-shaped channel, and the angle between the arc-shaped channel and the fluid channel close to the reaction chamber is less than 90 degrees.

[0024] In some embodiments, the exhaust channel can be led out slightly closer to the detection chamber. Because the exhaust channel is closer to the detection chamber, the pressure that the sample needs to overcome to enter the detection chamber during centrifugation can be reduced, making it easier for the sample to enter the detection chamber during centrifugation.

[0025] When the exhaust channel is led out from the fluid channel, the smaller the angle between the initial section and the fluid channel close to the reaction chamber, the less likely the fluid is to enter the exhaust channel. However, this angle cannot be too small, otherwise it may cause exhaust difficulties. It is preferred to use an arc-shaped channel at one end for transition, and the angle between the arc-shaped channel and the fluid channel close to the reaction chamber is less than 90 degrees.

[0026] In some embodiments, the exhaust passage has an inner diameter smaller than that of the fluid passage.

[0027] Furthermore, the chip body and the sub-chip are both provided with a main flow channel, and the outlet of the exhaust channel is connected to the main flow channel.

[0028] The outlet of the exhaust channel is connected to the main channel, which is equivalent to exhausting air to the main channel. The reaction chamber and the detection chamber do not need to be connected to the outside atmosphere. The atmosphere pressed out of the reaction chamber or the detection chamber is discharged back to the main channel, which is equivalent to the air pressure of the liquid-filled part being discharged to the unfilled part through the exhaust channel, which plays a role in controlling the flow of liquid. Moreover, after exhausting air to the main channel through the exhaust channel, the air pressure in the chip is balanced, and the sample entering the reaction chamber or the detection chamber is difficult to flow out of the reaction chamber, and it is difficult to reflux, forming a circulating closed environment. Since it is not connected to the outside world, it can effectively avoid aerosol contamination, making the test results more accurate and reliable, and the preparation process is simpler and easier, with low cost.

[0029] The process includes three steps: the first step is that the sample enters the main channel from the sample injection port; the second step is low-speed centrifugation to allow the sample to enter the reaction chamber from the main channel for reaction; the third step is that after the reaction is completed, the sample flows out of the reaction chamber through medium-speed centrifugation and enters the detection chamber for reaction and detection. Unlike the first setting method, when the second setting method is adopted, it is also necessary to control the flow of the sample by controlling the centrifugal rate. The sample enters the reaction chamber from the main channel through low-speed centrifugation (such as 100-1000 rpm), and then enters the detection chamber from the reaction chamber through medium-speed centrifugation (such as 1000-3000 rpm). The method of controlling the flow of samples in different chambers by controlling the centrifugal rate is simpler and easier to operate, and the whole process is more controllable, and the test results are more accurate.

[0030] In the first step, the sample is injected into the main channel from the injection port through a pipette or syringe. After filling the serpentine main channel, the sample will flow to the final waste liquid pool, the injection will stop, and the injection port will be sealed. This process is equivalent to the process of the sample filling the main channel, and it is also the process of the gas filled with liquid being discharged to the unfilled part of the main channel through the exhaust channel. Since the inner diameter of the branch channel connecting the main channel to the reaction chamber is small and there is a large difference with the inner diameter of the main channel, the sample cannot flow into the reaction chamber. Moreover, it is difficult to discharge the gas in the reaction chamber from the exhaust channel back to the main channel by relying solely on the injection pressure, so the sample will first stay in the main channel.

[0031] In the second step, after the sample completely fills the main channel, it is centrifuged clockwise at a low speed. The sample in the main channel enters the reaction chamber under the action of centrifugal force. Since the detection chamber does not have a separate exhaust channel, it is almost a surrounding sealed structure. Under low-speed centrifugation, it is difficult for the sample to overcome the gas pressure in the detection chamber, so it cannot flow into the detection chamber. At the same time, since the exhaust direction of the exhaust channel is opposite to the centrifugal direction, and the exhaust channel is higher than the fluid, the sample can only reach the intersection of the fluid channel and the exhaust channel at most in the second step, and it cannot continue to move forward, so that the volume of the sample entering the reaction chamber can be controlled. During the low-speed centrifugation process, the sample enters the reaction chamber, and the gas in the reaction chamber is discharged back to the main channel, which can also help the sample in the main channel flow into the reaction chamber. After low-speed centrifugation, the sample remains in the reaction chamber for amplification reaction, and the sealed state reaches pressure balance inside and outside. The sample in the reaction chamber can no longer flow from the reaction chamber to other areas, because it is necessary to have a large pressure to break the established internal and external pressure balance to flow out of the reaction chamber. Therefore, all samples will remain in the reaction chamber for reaction, and leakage or backflow is impossible.

[0032] In the third step, after the sample completes the amplification reaction in the reaction chamber, the centrifugal speed is increased. After medium-speed centrifugation, the initial pressure balance is broken, driving the sample to transfer from the reaction chamber to the detection chamber. At this time, since the exhaust direction of the exhaust channel is opposite to the centrifugal direction and the inner diameter of the exhaust channel is smaller, the sample will not enter the exhaust channel and will all flow to the detection chamber. Since the entire system is in a closed state, the liquid in the detection chamber will not reflux, so it can be stably used for detection.

[0033] Therefore, two stages of centrifugation are used throughout the process to complete multiple nucleic acid detection. The speeds of the first and second stages of centrifugation can differ greatly, and the control is stable. High-speed centrifugation (such as 3000-10000 rpm) is not required to avoid precipitation due to insufficient dissolution of pre-embedded freeze-dried or vitrified reagents due to high-speed centrifugation, thereby causing reaction failure and affecting the test results.

[0034] Furthermore, when the centrifugal microfluidic chip is placed horizontally, the outlet of the exhaust channel is located higher than the inlet.

[0035] The outlet of the exhaust channel is located higher than the inlet, which can further increase the difficulty of the fluid sample entering the exhaust channel, thereby helping to control the flow of liquid in the chip and facilitating the exhaust of gas from the reaction chamber and the detection chamber.

[0036] Furthermore, the chip body is circular; the main channels in the chip body and the sub-chip are arranged in a serpentine shape and bent into a ring, and the chip body, the ring, the sub-chip and the rotation center are coaxially arranged.

[0037] In some embodiments, the main flow channel adopts a serpentine flow channel with a large curvature and evenly spaced, which can help maintain the air pressure balance in the chip, smoothly control the flow of liquid, and help prevent the various detection units from directly interfering with each other.

[0038] In some embodiments, when the outlet of the exhaust channel is connected to the main channel, the main channel is arranged in a serpentine shape, which makes the main channel more curved and longer, so that the samples are first stably retained in the main channel.

[0039] Furthermore, the serpentine main flow channel includes U-shaped flow channels arranged at equal distances along a circular ring, the bottom end of the U-shaped flow channel is connected to the reaction chamber, and the top end of the U-shaped flow channel is connected to the outlet of the exhaust channel.

[0040] In some embodiments, a branch channel connected to the inlet of the reaction chamber is provided at the bottom of the U-shaped flow channel, and the top of the U-shaped flow channel is connected to the exhaust channel. The left and right sides of the U-shaped flow channel are longer, and the top is closer to the rotation center than the bottom, so that the bottom and top of the U-shaped flow channel are far apart. When the exhaust channel exhausts air to the top of the U-shaped flow channel, it will not immediately affect the air pressure balance at the bottom, which helps the sample to flow smoothly into the reaction chamber.

[0041] The U-shaped flow channels are evenly arranged, and the bottom end of each U-shaped flow channel is connected to a reaction chamber. Therefore, during centrifugation, the sample in each U-shaped flow channel will enter the corresponding reaction chamber under the action of centrifugal force, which is equivalent to the U-shaped flow channel evenly distributing the sample in advance, and can assist in controlling the volume of the sample entering the reaction chamber.

[0042] Furthermore, the main channel is not connected at the beginning and the end, the sample addition port is located at the starting end of the main channel, and a waste liquid pool is also provided at the end of the main channel.

[0043] When the sample adding port is located at the starting end of the main channel, the two ends of the main channel are not connected, and the sample adding port and the waste liquid pool are respectively set at the two ends, wherein the sample adding port is located at the starting end of the main channel and the waste liquid pool is located at the end of the main channel.

[0044] The waste liquid pool has a liquid storage function and is used to receive excess samples. When the sample fills the main channel, the excess sample will enter the waste liquid pool. When the second method is used, since the injection pressure is not enough to allow the sample to enter the reaction chamber, the excess sample will begin to enter the waste liquid pool after the sample fills the main channel. At this time, it is equivalent to prompting that the sample addition amount is sufficient and the sample addition can be stopped. Therefore, the waste liquid pool also has the effect of helping sample quantification.

[0045] In some methods, the surface of the sample loading port of the centrifugal microfluidic chip is covered with a transparent film to seal the sample. When loading the sample, the transparent film is pierced by a syringe to load the sample. After the sample fills the main channel, the surface of the sample loading hole needs to be covered with a transparent film to seal it.

[0046] Furthermore, the chip body and the sub-chip adopt an integrally formed structure and cannot be disassembled; when the sub-chip body is centrifugally rotated, the sub-chip can be centrifugally rotated along with the chip body.

[0047] In order to make the centrifugation process more stable and controllable, the chip body and the sub-chip adopt an integrated molding structure and cannot be disassembled.

[0048] Furthermore, the rotation center is a slot, and the slot enables the centrifugal microfluidic chip to be stuck on the rotation axis of the centrifugal drive device, so as to perform centrifugal rotation. The chip body and the sub-chip can be centrifugally rotated together under the drive of the slot.

[0049] In some embodiments, the slot is a circular slot with a protrusion, and the protrusion is in the shape of a triangle, trapezoid, etc. The rotating shaft on the detection device also has a fixed groove that matches the size of the slot, so that the centrifugal microfluidic chip is fixed on the rotating shaft through the slot and performs centrifugal rotation with the rotating shaft.

[0050] In some embodiments, the cross-section of the reaction chamber is circular.

[0051] The cross-sectional shape of the reaction chamber is set to be circular, so that the sample to be tested reacts and is discharged in the reaction chamber without leaving dead corners, and it is not easy to leave residues during the inflow and outflow processes.

[0052] In some embodiments, the reaction chamber is used for amplifying the target nucleic acid, and the reaction chamber contains a nucleic acid amplification reagent; the detection chamber is used for detecting the target nucleic acid, and the detection chamber contains a nucleic acid detection reagent.

[0053] In some embodiments, the reaction chamber can serve as an ERA amplification chamber, and the detection chamber can serve as an ERA detection chamber.

[0054] In some embodiments, the reaction chamber can be used as an ERA reaction chamber, and the detection chamber can be used as a CRISPR detection chamber.

[0055] In some embodiments, the reaction chamber can be used as an ERA reaction chamber, and the detection chamber can be used as an Ago detection chamber.

[0056] In some embodiments, the reaction chamber can be used as an ERA reaction chamber, and the detection chamber can be used as an RNase H detection chamber.

[0057] In some embodiments, the amplification reaction includes but is not limited to EPA, RPA, LAMP, NEAR, NASBA, HAD, TMA, SAT, RCR, etc., and the solid amplification reagent includes but is not limited to spherical, powdered, flaky or block preparations in the form of freeze-dried, dried, air-dried, etc.

[0058] In some embodiments, the cross-section of the detection chamber is approximately semicircular and larger than the reaction chamber, which can ensure that all samples in the reaction chamber enter the detection chamber.

[0059] In some embodiments, the detection reagents include but are not limited to various detection systems established by ERA, RPA, LAMP, NEAR, NASBA, HAD, TMA, SAT, PCR, hybridization probe technology, CRISPR, Ago, RNase H, etc., and the detection reagents are solid detection reagents, including but not limited to spherical, powdered, flaky or block preparations in the form of freeze-dried, dried, air-dried, etc.

[0060] On the other hand, the utility model provides a nucleic acid detection method, which uses the centrifugal microfluidic chip as described above for detection, and the detection method comprises the following steps:

[0061] (1) Place the centrifugal microfluidic chip horizontally and add the sample to be tested from the sample injection port;

[0062] (2) clamping the card slot of the centrifugal microfluidic chip on the rotating shaft of the detection device;

[0063] (3) low-speed centrifugation, the sample to be tested enters the reaction chamber of the centrifugal microfluidic chip from the sample loading area for nucleic acid amplification;

[0064] (4) centrifuging at a moderate speed to allow the sample to be tested after nucleic acid amplification to enter the detection chamber for reaction;

[0065] (5) Read the test results.

[0066] In step (2), the nucleic acid amplification is isothermal amplification, and a heating device is required to provide the reaction chamber with a suitable temperature required for isothermal amplification (such as 30-65° C.).

[0067] The centrifugal microfluidic chip with a sub-chip provided by the utility model has the following beneficial effects:

[0068] 1. One or more concentric circle sub-chips are set outside the chip body to achieve high-throughput detection of more samples and more detection indicators, thereby improving detection efficiency;

[0069] 2. By leading out an exhaust channel on the fluid channel between the reaction chamber and the detection chamber, and making the exhaust direction of the exhaust channel opposite to the rotating centrifugal direction and the position higher than the fluid channel, the flow of gas and liquid in the reaction chamber and the detection chamber can be effectively controlled, and the amount of sample entering the reaction chamber can be effectively controlled. Only two low-speed and medium-speed centrifugations are required to complete multiple nucleic acid detection, which is more convenient to operate and more accurate in test results.

[0070] 3. The exhaust channel is connected to the main channel, and the gas is directly discharged back to the main channel without connecting to the outside world, which can avoid aerosol pollution, make the manufacturing process more convenient and reduce costs;

[0071] 4. After entering each chamber, the sample to be tested can be stably retained and reacted, effectively preventing sample backflow, eliminating mutual interference or contamination, and providing guarantee for accurate detection;

[0072] 5. It has simple structure, compact size and convenient operation. It can meet the needs of rapid detection anytime, anywhere, and adapt to more simple detection environments. It truly achieves low-cost integration and is suitable for large-scale production applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Figure 1 is a front view of the centrifugal microfluidic chip in Example 1;

[0074] Figure 2 It is a back view of the centrifugal microfluidic chip in Example 1;

[0075] Figure 3 It is a stereoscopic diagram of the centrifugal microfluidic chip in Example 1;

[0076] Figure 4Schematic diagram of the detection unit structure in the centrifugal microfluidic chip in Example 1. DETAILED DESCRIPTION

[0077] The preferred embodiments of the present invention are described in further detail below in conjunction with the accompanying drawings. It should be noted that the embodiments described below are intended to facilitate the understanding of the present invention and do not have any limiting effect on the present invention. The raw materials and equipment used in the specific embodiments of the present invention are all known products and are obtained by purchasing commercially available products.

[0078] In the description of the present utility model, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are 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, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present utility model, unless otherwise specified, "multiple" means two or more.

[0079] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0080] Example 1: Nucleic acid multiplex detection centrifugal microfluidic chip with the second exhaust channel configuration

[0081] The structure of the nucleic acid multiplex detection centrifugal microfluidic chip provided in this embodiment is as follows Figures 1 to 4 As shown, Figure 1 It is a front view of the centrifugal microfluidic chip; Figure 2 It is the back view of the centrifugal microfluidic chip; Figure 3 It is a three-dimensional image of a centrifugal microfluidic chip; Figure 4 Schematic diagram of the detection unit structure in the centrifugal microfluidic chip.

[0082] like Figures 1 to 4As shown, the centrifugal microfluidic chip 1 for multiple nucleic acid detection provided in this embodiment includes a chip body 3 with a rotation center 2, and the chip body 3 is provided with a reaction chamber 4 for sample nucleic acid amplification and a detection chamber 5 for sample detection; the reaction chamber 4 and the detection chamber 5 are connected by a fluid channel 6, and the fluid channel 6 is also provided with an exhaust channel 7, which is led out from a position approximately in the middle of the fluid channel 6, and the exhaust channel 7 is used to control the flow of gas in the reaction chamber 4 or the detection chamber 5; the rotation center 2 is used to connect with a centrifugal drive device, so as to drive the centrifugal microfluidic chip 1 to centrifuge.

[0083] Any number of detection units 8 can be set on the centrifugal microfluidic chip 1 according to the project needs or the size of the chip, so as to realize the simultaneous detection of multiple targets. Each group of detection units 8 is provided with a reaction chamber 4 and a detection chamber 5, which can be applicable to the detection of a variety of different target analytes (such as a variety of different nucleic acid targets), and each group of detection units can realize multiple nucleic acid detection. During use, the centrifugal microfluidic chip 1 needs to be placed in a horizontal state in a matching detection device (centrifugal drive device), with the sample addition port 9 facing upward and placed horizontally, and the rotation center 2 is buckled and fixed with the rotating shaft of the detection device for centrifugation, so that the rotating shaft can drive the centrifugal microfluidic chip 1 to rotate centrifugally; at the same time, the detection device can also provide a heat source for the reaction chamber 4 of the centrifugal microfluidic chip 1 for heating; the fluorescent substance produced after the sample reaction in the centrifugal microfluidic chip 1 can also be detected by the detection device, and the detection result can be read.

[0084] The fluid channel 6 connected between the reaction chamber 4 and the detection chamber 5 refers to the channel connecting the outlet 9 of the reaction chamber 4 and the inlet 10 of the detection chamber 5. The exhaust channel 7 includes an inlet 11 and an outlet 12, wherein the inlet 11 is the connection between the fluid channel 6 and the exhaust channel 7, and the outlet 12 is the other end of the exhaust channel 7; the outlet 12 is closer to the rotation center 2 than the inlet 11, so that the exhaust direction of the exhaust channel 7 is opposite to the centrifugal direction of rotation or at least partially opposite. When the centrifugal microfluidic chip 1 is centrifuged, the flow direction of the fluid sample under the centrifugal action is emitted from the center of the circle outward. At this time, since the exhaust channel 7 is drawn out from the fluid channel 6 between the reaction chamber 4 and the detection chamber 5 and approaches the rotation center 2, the exhaust direction is opposite to the centrifugal direction. It is difficult for the fluid sample to enter the exhaust channel 7 during centrifugation, but it accurately enters the corresponding chamber along the centrifugal direction.

[0085] like Figure 4As shown, the exhaust channel 7 is led out from the middle of the fluid channel or the position close to the detection chamber 5, and the initial section led out is an arc-shaped channel 13, and the angle 14 between the arc-shaped channel 13 and the fluid channel close to the reaction chamber 4 is less than 90 degrees. The exhaust channel 7 can be led out slightly close to the detection chamber 5, because the exhaust channel 7 is close to the detection chamber, which can reduce the pressure that the sample needs to overcome to enter the detection chamber 5 during centrifugation, and the sample is easier to enter the detection chamber 5 during centrifugation. When the exhaust channel 7 is led out from the fluid channel 6, the smaller the angle 14 between the initial section and the fluid channel close to the reaction chamber 4, the less likely the fluid is to enter the exhaust channel 6, but this angle 14 cannot be too small, otherwise it may cause exhaust difficulties. It is preferred to use an arc-shaped channel 13 at one end for transition, and the angle between the arc-shaped channel 13 and the fluid channel close to the reaction chamber 4 is less than 90 degrees. Preferably, the inner diameter of the exhaust channel 7 is smaller than the inner diameter of the fluid channel 6, which can further prevent the sample from entering the exhaust channel 7 during centrifugation.

[0086] The outlet 12 of the exhaust channel 7 is connected to the main channel 16 of the chip body 3, and exhaust is directed to the main channel 16 (see Figures 1 to 4 ). When this setting is adopted, only two centrifugations are required to complete the nucleic acid multiple detection in the whole process. Neither the reaction chamber 4 nor the detection chamber 5 needs to be connected to the outside atmosphere. The exhaust channel 7 is directly connected to the main channel 16, and the atmosphere pressed out of the reaction chamber 4 or the detection chamber 5 is discharged back to the main channel 16, which is equivalent to the air pressure of the liquid-filled part being discharged to the unfilled part through the exhaust channel 7, thereby controlling the flow of liquid. Moreover, after exhausting the gas to the main channel 16 through the exhaust channel 7, the air pressure balance is reached in the chip 1, and the sample entering the reaction chamber 4 or the detection chamber 5 is also difficult to flow out of the reaction chamber 4, and it is difficult to reflux, forming a circulating closed environment. Moreover, compared with the setting method in which the exhaust channel outlet 12 provided in Example 1 or 2 is connected to the outside world, since it is not connected to the outside world, it can effectively avoid aerosol contamination, making the test results more accurate and reliable. At the same time, since the steps of preparing air holes and covering the waterproof breathable membrane 15 are omitted, the preparation process is simpler and easier, and the cost is lower.

[0087] When this setting is adopted, the process of the flow and detection of the sample to be tested in the centrifugal microfluidic chip 1 includes three steps: the first step is that the sample enters the main channel 16 from the sample injection port 17; the second step is low-speed centrifugation to allow the sample to enter the reaction chamber 4 from the main channel 16 for reaction; the third step is that after the reaction is completed, the sample flows out of the reaction chamber 4 through medium-speed centrifugation and enters the detection chamber 5 for reaction and detection. Different from the first setting, when the second setting is adopted, it is also necessary to control the flow of the sample by controlling the centrifugal rate, so that the sample enters the reaction chamber 5 from the main channel 16 through low-speed centrifugation (such as 100 to 1000 rpm), and then enters the detection chamber 5 from the reaction chamber 4 through medium-speed centrifugation (such as 1000 to 3000 rpm). The method of controlling the flow of samples in different chambers by controlling the centrifugal rate is simpler and easier to operate, and the whole process is more controllable, and the detection results are more accurate.

[0088] like Figures 1 to 4When this setting is adopted, in the first step, the sample is injected from the sample port 17 into the main channel 16 through a pipette or a syringe. After filling the serpentine main channel 16, the sample will flow to the final waste liquid pool 18, the injection will be stopped, and the sample port 17 will be sealed. This process is equivalent to the process of the sample filling the main channel 16, and it is also the process of the gas filled with liquid being discharged to the unfilled main channel 16 through the exhaust channel 7. Since the inner diameter of the branch channel 19 connecting the main channel 16 to the reaction chamber 4 is small, and there is a large difference with the inner diameter of the main channel 16, the sample cannot flow into the reaction chamber 4. Moreover, it is difficult to discharge the gas in the reaction chamber 4 back to the main channel 16 from the exhaust channel 7 by relying solely on the injection pressure, so the sample will first stay in the main channel 16. In the second step, after the sample completely fills the main channel 16, it is centrifuged instantaneously at a low speed clockwise (such as 100 to 1000 rpm, preferably 500 rpm in this embodiment). The sample in the main channel 16 enters the reaction chamber 4 under the action of centrifugal force. Since the detection chamber 5 does not have a separate exhaust channel 7, it is almost an enclosed sealed structure. Under low-speed centrifugation, it is difficult for the sample to overcome the gas pressure in the detection chamber 5, so it cannot flow into the detection chamber 5. At the same time, since the exhaust direction of the exhaust channel 7 is opposite to the centrifugal direction, and the exhaust channel 7 is higher than the fluid channel 6, the sample can only reach the intersection of the fluid channel 4 and the exhaust channel 7 at most in the second step, and cannot continue to move forward, thereby controlling the volume of the sample entering the reaction chamber 4. During the low-speed centrifugation process, the sample enters the reaction chamber 4, and the gas in the reaction chamber 4 is discharged back to the main channel 16, which can also help the sample in the main channel 16 flow into the reaction chamber 4. After low-speed centrifugation, the sample is retained in the reaction chamber 4 for amplification reaction, and the sealed state reaches pressure balance inside and outside. The sample in the reaction chamber 4 can no longer flow from the reaction chamber 4 to other areas, because it is bound to require a large pressure to break the established internal and external pressure balance to flow out of the reaction chamber 4. Therefore, all samples will remain in the reaction chamber 4 for reaction, and leakage or backflow is impossible. In the third step, after the sample completes the amplification reaction in the reaction chamber 4, the centrifugal speed is increased, and the initial pressure balance is broken by medium-speed centrifugation (such as 1000-3000 rpm, preferably 2000 rpm in this embodiment), driving the sample from the reaction chamber 4 to the detection chamber 5. At this time, since the exhaust direction of the exhaust channel 7 is opposite to the centrifugal direction, and the inner diameter of the exhaust channel 7 is smaller, the sample will not enter the exhaust channel 7, and will all flow to the detection chamber 5. Since the entire system is in a closed state, the liquid in the detection chamber 5 will not reflux, so it is stable for detection.

[0089] Therefore, this setting adopts two-stage centrifugation to complete multiple nucleic acid detection. The speed of the first-stage centrifugation and the second-stage centrifugation can be greatly different, and the control is stable. There is no need for high-speed centrifugation (such as 3000-10000 rpm), which can avoid the precipitation of pre-embedded freeze-dried or vitrified reagents due to insufficient dissolution caused by high-speed centrifugation, thereby causing reaction failure and affecting the detection results. There is no need to connect to the outside world to avoid aerosol contamination, and it is more convenient to manufacture and has lower cost.

[0090] The chip body 3 is circular, the main flow channel 16 is arranged in a serpentine shape and bent into a ring, and the chip body 3, the ring and the rotation center 2 are coaxially arranged. The main flow channel 16 adopts a serpentine flow channel with a large curvature and evenly spaced, which can help maintain the air pressure balance in the chip 1, smoothly control the flow of liquid, and help prevent the detection units 8 from directly interfering with each other.

[0091] like Figures 1 to 4 When the outlet 12 of the exhaust channel 7 is connected to the main channel 16, the main channel 16 is arranged in a serpentine shape, which makes the main channel 16 more curved and longer, so that the samples are first stably stored in the main channel 16. The main channel 16 arranged in a serpentine shape includes U-shaped channels 20 arranged at equal distances along the ring, and the bottom end 21 of the U-shaped channel 20 is connected to the reaction chamber 4; when the outlet 12 of the exhaust channel 7 is connected to the main channel 16, the connected part is the top end 22 of the U-shaped channel 20.

[0092] Preferably, the bottom 21 of the U-shaped flow channel 20 is provided with a branch flow channel 19 connected to the entrance of the reaction chamber, and the top 22 of the U-shaped flow channel 20 is connected to the exhaust channel 7. The left and right sides of the U-shaped flow channel 20 are longer, and the top 22 is closer to the rotation center 2 than the bottom 21, so that the bottom 21 and the top 22 of the U-shaped flow channel 20 are separated by a large distance. When the exhaust channel 7 exhausts the top 22 of the U-shaped flow channel 20, it will not immediately affect the pressure balance at the bottom 21, which helps the sample to flow smoothly into the reaction chamber 4. Figures 1 to 3 The U-shaped flow channels 20 are evenly arranged, and the bottom end 21 of each U-shaped flow channel 20 is connected to a reaction chamber 4. Therefore, during centrifugation, the sample in each U-shaped flow channel 20 will enter the corresponding reaction chamber 4 under the action of centrifugal force, which is equivalent to the U-shaped flow channel 20 evenly distributing the sample in advance, which can assist in controlling the volume of the sample entering the reaction chamber 4.

[0093] Preferably, the main channel 16, the branch channel 19 (including the fluid channel 6) and the permeable channel 7 all adopt a gradually narrowing microchannel structure to prevent the sample droplets from being unevenly distributed due to too fast sample droplets; the width of the main channel 16 ranges from 500μm to 1000μm, and the depth ranges from 500μm to 1000μm; the width of the branch channel 19 ranges from 400μm to 800μm, and the depth ranges from 200μm to 400μm; the width of the permeable channel 7 ranges from 50μm to 500μm, and the depth ranges from 100 to 300μm. In this embodiment, the widths of the main channel 16, the branch channel 19 and the permeable channel 7 are 800um, 400um and 200μm, respectively, and the depths are 500um, 400um and 200μm, respectively.

[0094] The main channel 16 is provided with a sample adding port 17 (including a first sample adding port 171 in the chip body 3 and a second sample adding port 172 in the sub-chip 27), as shown in FIG. Figures 1 to 4 , the sample addition port 17 is located at the starting end 23 of the main channel 16, and the end 24 of the main channel 16 is also provided with a waste liquid pool 18 (including the first waste liquid pool 181 in the chip body 3 and the second waste liquid pool 182 in the sub-chip 27), and the two ends of the main channel 16 are not connected. The waste liquid pool 18 has a liquid storage function, which is used to receive excess samples. When the sample is filling the main channel 16, the excess sample will enter the waste liquid pool 18. Since the injection pressure is not enough to allow the sample to enter the reaction chamber 4, after the sample fills the main channel 16, the excess sample will begin to enter the waste liquid pool 18, which is equivalent to prompting that the sample addition amount is sufficient and the sample addition can be stopped. Therefore, the waste liquid pool 18 also has the effect of helping the sample quantification.

[0095] The surface of the sample port 17 of the centrifugal microfluidic chip 1 is covered with a transparent film for sealing. When adding samples, the transparent film is pierced by a syringe to add samples. After the sample fills the main channel 16, the surface of the sample port 17 needs to be covered with a transparent film for sealing.

[0096] like Figures 1 to 4The centrifugal microfluidic chip 1 provided has a sub-chip 27 disposed outside the chip body 3. The sub-chip 27 is a concentric ring chip located outside the chip body 3. The sub-chip 27 is also provided with a main channel 16, a reaction chamber 4 and a detection chamber 5; when the chip body 3 is centrifugally rotated, the sub-chip 27 can be centrifugally rotated together with the chip body 3. The sub-chip 27 is a concentric ring chip located outside the chip body 3. Of course, if necessary, sub-chips can be further disposed outside the sub-chip 27. The chip body 3 and the sub-chip 27 can be directly molded and integrally formed in one chip 1 and cannot be disassembled. The sub-chip 27, the chip body 3 and the entire microfluidic chip 1 are all in the same plane. The sub-chip 27 is located outside the chip body 3 and has a larger diameter, so more groups of detection units 8 can be set up. At the same time, the sub-chip 27 can also be provided with a sample addition port 17 and a waste liquid pool 18 to independently perform multiple nucleic acid detections. It can detect samples different from the chip body 3, realize simultaneous detection of multiple samples, and can detect more indicators at the same time (each detection unit 8 can detect a nucleic acid target), significantly increasing the detection throughput and improving the detection efficiency.

[0097] like Figures 1 to 4 , the rotation center 2 is a slot 28, and the slot 28 can be clamped on the rotating shaft of the detection device for centrifugal rotation, thereby driving the entire chip to rotate centrifugally. Preferably, the slot 28 is a circular slot with a protrusion 29, and the shape of the protrusion 29 is a triangle, a trapezoid, etc. The rotating shaft on the detection device also has a fixing groove that can match the size of the slot 28, so that the centrifugal microfluidic chip 1 is fixed on the rotating shaft through the slot 28, and centrifugally rotates with the rotating shaft.

[0098] Preferably, the cross-sectional shape of the reaction chamber 4 is circular, so that the sample to be tested reacts and is discharged in the reaction chamber 4 without leaving dead corners, and it is not easy to leave residues during the inflow and outflow processes. The cross-sectional shape of the detection chamber 5 is approximately semicircular and larger than the reaction chamber 4, which can ensure that all samples in the reaction chamber 4 enter the detection chamber 5.

[0099] In some embodiments, the reaction chamber 4 is used for amplifying the target nucleic acid, and the reaction chamber 4 contains a nucleic acid amplification reagent, and the detection chamber 5 is used for detecting the target nucleic acid, and the detection chamber 5 contains a nucleic acid detection reagent.

[0100] The centrifugal microfluidic chip 1 provided in this embodiment is designed with multiple chips (chip body 3 and sub-chip 27), each chip operates independently and is combined with an active drive mode. While accurately controlling the re-dissolution and mixing process of samples and reagents, it has the characteristics of ultra-high throughput and can be used for multi-sample and multi-index detection (such as detecting multiple different respiratory pathogen screening fields of multiple patient samples).

[0101] Example 2: Method for using a centrifugal microfluidic chip for multiple nucleic acid detection

[0102] The centrifugal microfluidic chip provided in Example 1 is used to perform multiple nucleic acid detection, comprising the following steps:

[0103] Step 1: Add sample and re-dissolve

[0104] The pipette is used to add different test samples to the first sample addition hole 171 and the second sample addition hole 172. Driven by the air pressure of the pipette, the sample to be tested will be evenly distributed along the main channel 16, and the excess liquid will enter the waste liquid pool 18. When the main channel 16 is completely filled, the sample addition port is closed with a transparent film. Due to the difference in the pore size between the main channel 16 and the branch channel 19, the liquid cannot enter the reaction chamber 4.

[0105] Step 2: Amplification phase

[0106] The sealed centrifugal microfluidic chip 1 is placed in parallel in the centrifugal drive device of the detection device, and centrifuged clockwise at a low speed (the speed is 500 / min), and the sample to be tested is distributed to the reaction chamber 4 through the main channel 16; at this time, the chip is heated, and the nucleic acid in the sample to be tested will undergo an amplification reaction at a certain temperature;

[0107] Step 3: Detection reaction

[0108] After step 2 is completed, the centrifugal drive device of the detection device is started again and the centrifugal speed is increased (the speed is 1500 rpm), and the sample to be tested is transferred from the reaction chamber 4 to the corresponding detection chamber 5 under the drive of centrifugal force; after the amplification product is mixed with the detection reagent, a detection reaction will occur at a certain temperature, and the detection reaction includes but is not limited to a variety of detection systems established by hybridization probe technology, CRISPR, Ago, RNaseH, etc.;

[0109] Step 4: Data reading

[0110] After step 3 is completed, the fluorescence intensity on the detection channel of the centrifugal microfluidic chip 1 is read by the optical device of the detection device to obtain the detection result.

[0111] According to the detection requirements, the fixed amplification reagent used for nucleic acid amplification in the reaction chamber 4 and the detection material used for detection in the detection chamber 5 include freeze-dried balls, freeze-dried powder or quality control internal standard reagent.

[0112] Both the amplification reaction and the detection reaction need to be performed at a certain temperature. Therefore, in step 2, a heating device is required to provide a suitable temperature for the centrifugal microfluidic chip 1. For example, an isothermal amplification reaction needs to provide a reaction temperature of 30 to 65°C.

[0113] Example 3: Verification of the detection effect of the centrifugal microfluidic chip for multiple nucleic acid detection

[0114] This embodiment adopts embodiment 1 ( Figures 1 to 4) centrifugal microfluidic chip for typing detection, and ERA-CRISPR detection technology (enzymatic recombinant amplification combined with CRISPR detection technology) was used to detect respiratory pathogen nucleic acid (influenza A virus, influenza B virus, respiratory syncytial virus, adenovirus, human rhinovirus, Mycoplasma pneumoniae, human metapneumovirus, parainfluenza virus) in blood specimens suspected of respiratory tract infection, and qPCR detection method (commercial reagent) was used for comparative verification. The oral swab was lysed by a sample releaser, and the lysate obtained was used as a template. The same template loading amount was used to amplify and detect the sample using a microfluidic chip device and a qPCR detection method, respectively. In the ERA-CRISPR detection technology, the amplification chamber in the chip device was pre-loaded with ERA freeze-dried microspheres containing specific amplification primers, and the detection chamber was pre-loaded with freeze-dried microspheres containing a specific CRISPR detection system. Whether the sample contains the corresponding pathogenic microorganism nucleic acid is determined, and the results are shown in Table 1.

[0115] Table 1. Centrifugal microfluidic chip detection performance verification list

[0116]

[0117] As can be seen from Table 1, when other conditions are the same, the detection results of the centrifugal microfluidic chip device of Example 1 are consistent with the results of the qPCR detection method, but it is more convenient and quick to use, has a lower comprehensive use cost, and is more suitable for on-site detection in the wild and special environments.

[0118] The technical features of the above-described embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the technical features in the above-described embodiments are not 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. Although the utility model is disclosed as above, the utility model is not limited thereto. For example, it can be expanded according to its scope of application in the field of microfluidics. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the utility model. Therefore, the scope of protection of the utility model shall be subject to the scope defined by the claims. The contents of the articles, patents, patent applications and all other documents and electronically available information described or recorded herein are included in full here for reference to some extent, just as each individual publication is specifically and individually pointed out for reference. The applicant reserves the right to incorporate any and all materials and information from any such articles, patents, patent applications or other documents into this application.

Claims

1. A centrifugal microfluidic chip, characterized in that: It includes a chip body with a rotation center and one or more sub-chips. The sub-chip is a concentric ring chip located outside the chip body. The rotation center is used to connect with a centrifugal drive device to drive the centrifugal microfluidic chip to centrifuge. The chip body and the sub-chip are both provided with a reaction chamber for sample nucleic acid amplification and a detection chamber for sample detection.

2. The centrifugal microfluidic chip according to claim 1, characterized in that: The reaction chamber and the detection chamber are connected via a fluid channel, and an exhaust channel is also provided on the fluid channel. The exhaust channel is used to control the flow of gas in the reaction chamber or the detection chamber.

3. The centrifugal microfluidic chip according to claim 2, characterized in that: The exhaust channel includes an inlet and an outlet, the inlet is the connection between the fluid channel and the exhaust channel, and the outlet is the other end of the exhaust channel; the outlet is closer to the rotation center than the inlet, so that the exhaust direction of the exhaust channel is opposite to or at least partially opposite to the centrifugal direction of rotation.

4. The centrifugal microfluidic chip according to claim 3, characterized in that: The chip body and the sub-chip are both provided with a main flow channel, and the outlet of the exhaust channel is connected with the main flow channel.

5. The centrifugal microfluidic chip according to claim 4, characterized in that: When the centrifugal microfluidic chip is placed horizontally, the outlet of the exhaust channel is located higher than the inlet.

6. The centrifugal microfluidic chip according to claim 5, characterized in that: The chip body is circular; the main channels in the chip body and the sub-chip are arranged in a serpentine shape and bent into a ring; the chip body, the ring, the sub-chip and the rotation center are coaxially arranged.

7. The centrifugal microfluidic chip according to claim 6, characterized in that: The serpentine main flow channel includes U-shaped flow channels arranged at equal distances along a circular ring, the bottom end of the U-shaped flow channel is connected to the reaction chamber, and the top end of the U-shaped flow channel is connected to the outlet of the exhaust channel.

8. The centrifugal microfluidic chip according to claim 7, characterized in that: The main channel is not connected at the beginning and the end, the sample adding port is located at the starting end of the main channel, and a waste liquid pool is also arranged at the end of the main channel.

9. The centrifugal microfluidic chip according to claim 8, characterized in that: The chip body and the sub-chip adopt an integrally formed structure and cannot be disassembled; when the sub-chip body rotates centrifugally, the sub-chip can rotate centrifugally along with the chip body.

10. The centrifugal microfluidic chip according to claim 9, characterized in that: The rotation center is a slot, and the slot enables the centrifugal microfluidic chip to be stuck on the rotation axis of the centrifugal drive device, thereby performing centrifugal rotation.

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