A microfluidic chip for rapid PCR and its applications

Abstract

This invention provides a microfluidic chip for rapid PCR and its application. The microfluidic chip includes a microfluidic chip body and a chip cover. The microfluidic chip body has grooves forming a sample dispensing port (1), a reaction area (2), and a bubble collection groove (3). The bubble collection groove (3) includes a first connection channel (31), a second connection channel (32), and a bubble collection groove body (33). The microfluidic chip for rapid PCR can complete the PCR amplification reaction in a short time. The microfluidic chip is easy to use, requires no professional equipment or operators, and has advantages such as low cost, low sample volume, high efficiency, and disposableness.

Description

Technical Field

[0001] This invention belongs to the field of microfluidic nucleic acid analysis technology, specifically relating to a microfluidic chip for rapid PCR and its applications. Background Technology

[0002] Polymerase chain reaction (PCR) is used to amplify DNA fragments located between two known sequences, similar to the replication process of natural DNA. Using the DNA molecule to be amplified as a template and a pair of oligonucleotide fragments complementary to the 5' and 3' ends of the template as primers, DNA polymerase extends the DNA along the template strand according to a semi-conservative replication mechanism until new DNA is synthesized. Repeating this process amplifies the target DNA fragment. Real-time quantitative PCR has become a key technology in gene research due to its high sensitivity, high specificity, short window period, and low cost, and is widely used in fields such as food safety testing, forensic identification, pet healthcare, and epidemic prevention and control.

[0003] Traditional PCR amplification commonly uses well plates as sample carriers, which suffers from slow heating and cooling rates. Cooling relies solely on natural convection, resulting in lengthy temperature transition times. Heating plates are also expensive and easily damaged. Furthermore, PCR requires high sensitivity and is susceptible to environmental interference. In addition, the large quantities of reactants required hinder cost reduction.

[0004] Therefore, a microfluidic chip for rapid PCR that can significantly shorten the heating and cooling time, reduce the amount of reactant samples, increase the analysis speed, reduce the cost, and is disposable has important application prospects. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a microfluidic chip for rapid PCR and its applications. The microfluidic chip of this invention can complete PCR amplification reactions in a short time. The microfluidic chip is easy to use, requires no specialized equipment or operators, and offers advantages such as low cost, low sample volume, high efficiency, and disposable nature.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a microfluidic chip for rapid PCR, the microfluidic chip comprising: a microfluidic chip body and a chip cover;

[0008] The microfluidic chip body has grooves, which form a sample dispensing port 1, a reaction area 2, and a bubble collection groove 3;

[0009] The bubble collecting tank 3 includes a first connecting channel 31, a second connecting channel 32, and a bubble collecting tank body 33.

[0010] In this invention, the microfluidic chip is as follows: Figure 1 As shown: Sample inlet 1, reaction zone 2, bubble collection tank 3. Matching heating components are as follows... Figure 2 As shown: H represents the high-temperature zone and L represents the low-temperature zone. After the sample is manually added through the sample inlet 1 and the inlet is sealed, the sample enters the reaction zone 2. The heating component is controlled to create a self-circulation between the high-temperature liquid and the low-temperature liquid (the high-temperature liquid has a lower density and the low-temperature liquid has a higher density). The PCR amplification effect can be achieved through thermal convection.

[0011] In addition, during the heating process, the liquid evaporates into bubbles. Due to their low density, these bubbles will flow to the bubble collection tank 3 at room temperature, thus not affecting the reaction. If multi-stage temperature control is involved, multiple heating components can be used to achieve precise temperature control.

[0012] In this invention, the tiny bubbles generated in the reaction zone 2 rise into the bubble collection tank 3. The shape of the bubble collection tank 3 enables efficient collection of bubbles and reduces bubble residue in the reaction zone 2.

[0013] Preferably, the microfluidic chip body is made of plastic material.

[0014] Preferably, the chip cover is made of plastic material.

[0015] Preferably, the sample application port 1 is used to add the PCR reaction solution to the reaction area 2.

[0016] Preferably, the reaction region 2 is used for the self-circulation of the PCR reaction solution, providing a site for PCR amplification; the reaction region 2 is divided into a high-temperature reaction region and a low-temperature reaction region, and the liquid flows under the influence of gravity and liquid temperature.

[0017] Preferably, the bubble collection tank 3 is used to collect and store bubbles generated by the PCR reaction solution in the reaction zone 2 during its self-circulation.

[0018] In a second aspect, the present invention provides a microfluidic chip device for rapid PCR, the microfluidic chip device comprising: the microfluidic chip for rapid PCR described in the first aspect, a temperature control unit, a signal detection unit, and a data processing and control unit.

[0019] Preferably, the temperature control unit includes a heating component and a temperature sensor.

[0020] Preferably, the heating assembly includes 1-4 (e.g., 1, 2, 3, or 4) low-temperature zones and 1-4 (e.g., 1, 2, 3, or 4) high-temperature zones; the low-temperature zones and high-temperature zones are distributed alternately; the temperature range of the low-temperature zones is 15-50℃ (e.g., 15℃, 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, or 50℃, etc.); the temperature range of the high-temperature zones is 65-150℃ (e.g., 65℃, 70℃, 75℃, 80℃, 85℃, 90℃, 95℃, 100℃, 105℃, 110℃, 115℃, 120℃, 125℃, 130℃, 135℃, 140℃, 145℃, or 150℃, etc.).

[0021] Preferably, the temperature sensor is used to detect and output the temperature of the reaction region 2.

[0022] Preferably, the temperature control unit is attached to the microfluidic chip body, and the temperature control unit is used to control the temperature of the microfluidic chip body and change the temperature of the reaction region 2 in the microfluidic chip body.

[0023] Preferably, the signal detection unit comprises an excitation light source, an optical transmission unit, and a photodetector; the signal detection unit is used to detect and output the fluorescence signal in the reaction region 2.

[0024] Preferably, the data processing and control unit is used to process, store, and display the data output by the temperature control unit and the signal detection unit.

[0025] Preferably, the heating assembly consists of a low-temperature zone and a high-temperature zone;

[0026] Alternatively, the heating assembly may consist of two low-temperature zones and two high-temperature zones;

[0027] Alternatively, the heating assembly may consist of three low-temperature zones and three high-temperature zones;

[0028] Alternatively, the heating assembly may consist of four low-temperature zones and four high-temperature zones.

[0029] In this invention, since the cross-section of the microfluidic chip is axially symmetric, the low-temperature zone can be located on either the left or right side of the microfluidic chip. Taking the low-temperature zone being located on the left side of the microfluidic chip as an example, when the heating component consists of one low-temperature zone and one high-temperature zone, the liquid density in the high-temperature zone of the heating component is low, and the liquid density in the low-temperature zone of the heating component is high. Under the influence of gravity and liquid density, the liquid flows from the low-temperature zone to the high-temperature zone on the lower side of the reaction region 2, and from the high-temperature zone to the low-temperature zone on the upper side of the reaction region 2, thereby realizing the self-circulation of the PCR amplification reaction solution and achieving PCR amplification during the circulation.

[0030] In this invention, since the cross-section of the microfluidic chip is axially symmetric, the low-temperature zone 1 can be located on either the left or right side of the microfluidic chip. Taking the low-temperature zone 1 located on the left side of the microfluidic chip as an example, when the heating assembly consists of two low-temperature zones and two high-temperature zones, the low-temperature zone 1 is located on the upper left side of the reaction region 2, the high-temperature zone 1 is located on the upper right side of the reaction region 2, the low-temperature zone 2 is located on the lower right side of the reaction region 2, and the high-temperature zone 2 is located on the lower left side of the reaction region 2, with the low-temperature and high-temperature zones arranged alternately. The temperature distribution is: high-temperature zone 1 > high-temperature zone 2 > low-temperature zone 1 > low-temperature zone 2; the liquid density distribution is: low-temperature zone 2 > low-temperature zone 1 > high-temperature zone 2 > high-temperature zone 1. On the left side of the reaction region 2, under the influence of gravity and liquid density, the liquid flows from the low-temperature zone 1 to the high-temperature zone 2, and on the upper side of the reaction region 2, the liquid flows from the high-temperature zone 1 to the low-temperature zone 1, realizing the self-circulation of the PCR amplification reaction solution, and achieving PCR amplification in the circulation.

[0031] In this invention, since the cross-section of the microfluidic chip is axially symmetric, the low-temperature zone can be located on either the left or right side of the microfluidic chip. Taking low-temperature zone 1 located on the left side of the microfluidic chip as an example, when the heating assembly consists of three low-temperature zones and three high-temperature zones, low-temperature zone 1, high-temperature zone 2, and low-temperature zone 3 are located on the left side of the microfluidic chip, and high-temperature zone 1, low-temperature zone 2, and high-temperature zone 3 are located on the right side of the microfluidic chip. The low-temperature and high-temperature zones are arranged alternately. The temperature order is: high-temperature zone 1 > high-temperature zone 2 > high-temperature zone 3 > low-temperature zone 1 > low-temperature zone 2 > low-temperature zone 3. The liquid density order is: low-temperature zone 3 > low-temperature zone 2 > low-temperature zone 1 > high-temperature zone 3 > high-temperature zone 2 > high-temperature zone 1. Under the influence of gravity and liquid density, on the left side of reaction region 2, the liquid flows from low-temperature zone 1 to high-temperature zone 2; on the lower side of reaction region 2, the liquid flows from low-temperature zone 3 to high-temperature zone 3, realizing the self-circulation of the PCR amplification reaction solution, and PCR amplification is achieved in the circulation.

[0032] In this invention, because the cross-section of the microfluidic chip is axially symmetric, the low-temperature zone can be located on either the left or right side of the microfluidic chip. Taking low-temperature zone 1 located on the left side of the microfluidic chip as an example, when the heating assembly consists of four low-temperature zones and four high-temperature zones, low-temperature zone 1, high-temperature zone 2, low-temperature zone 3, and high-temperature zone 4 are located on the left side of the microfluidic chip, and high-temperature zone 1, low-temperature zone 2, high-temperature zone 3, and low-temperature zone 4 are located on the right side of the microfluidic chip. The liquid in each region will flow according to its temperature and density to achieve the PCR reaction. However, with the increase of heating modules, theoretically, some areas will have flow dead zones. However, as the liquid flows in other temperature zones of the reaction zone, it will further promote the flow of liquid in adjacent areas. Therefore, the theoretical problem of flow dead zones will be alleviated to some extent. However, compared with chips containing three or fewer heating components, chips containing four or more heating components have relatively poor amplification effects.

[0033] Thirdly, the present invention provides a nucleic acid amplification method, comprising: amplification using the microfluidic chip device for rapid PCR described in the second aspect.

[0034] Preferably, the steps of the nucleic acid amplification method include:

[0035] (a) The PCR amplification reaction solution is injected into the microfluidic chip body through the sample dispensing port 1. The temperature of the microfluidic chip body is controlled by the temperature control unit to change the temperature of the reaction area 2 in the microfluidic chip body. The PCR amplification reaction solution generates self-circulation in the reaction area 2 to achieve PCR amplification effect. The bubbles generated in the self-circulation enter the bubble collection tank 3 along the liquid flow direction. The fluorescence signal in the reaction area 2 is detected and output by the signal detection unit.

[0036] (b) A data processing and control unit is used to process, store and display the data output by the signal detection unit.

[0037] In this invention, the nucleic acid amplification method is a fully enclosed reaction, which can effectively avoid aerosol contamination. A temperature control unit is used for temperature control, and the high-temperature liquid and low-temperature liquid will generate a self-circulation (the high-temperature liquid has a lower density, and the low-temperature liquid has a higher density). PCR amplification can be achieved through thermal convection, simplifying the PCR process. The temperature control unit can accurately and in multiple stages control the heating temperature, significantly shortening the heating and cooling time and improving the analysis speed. The microfluidic chip of this invention enables rapid PCR detection of trace amounts of liquid, requiring low reactant quantities and minimizing detection costs.

[0038] Fourthly, the present invention provides the application of the microfluidic chip for rapid PCR described in the first aspect and / or the microfluidic chip device for rapid PCR described in the second aspect in the preparation of PCR detection products.

[0039] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] (1) Rapid PCR can be completed in a short time.

[0042] (2) The entire process is a closed reaction, which can effectively avoid aerosol pollution.

[0043] (3) Only a small amount of liquid (a few microliters) is required.

[0044] (4) Low cost and not easily damaged.

[0045] (5) The heating temperature can be accurately and in multiple stages. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of a microfluidic chip used for rapid PCR. In the diagram, 1 is the sample dispensing port, 2 is the reaction area, 3 is the bubble collection tank, 31 is the first connection channel, 32 is the second connection channel, and 33 is the main body of the bubble collection tank.

[0047] Figure 2 This is a diagram of the heating components (2 heating components) used with a rapid PCR microfluidic chip.

[0048] Figure 3 This is a diagram of the heating components (4 heating components) used with a rapid PCR microfluidic chip.

[0049] Figure 4 This is a diagram of the heating components (6 heating components) used with a rapid PCR microfluidic chip.

[0050] Figure 5 This is a diagram of the heating components (8 heating components) used with a rapid PCR microfluidic chip.

[0051] Figure 6 It is a microfluidic chip with a semi-circular bubble collection tank.

[0052] Figure 7 It is a microfluidic chip with a square bubble collection tank.

[0053] Figure 8 It is a microfluidic chip with a hollow arc-shaped bubble collection tank. Detailed Implementation

[0054] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0055] Where specific techniques or conditions are not specified in the examples, they shall be performed in accordance with the techniques or conditions described in the literature in this field, or in accordance with the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased through legitimate channels.

[0056] Example 1: A microfluidic chip for rapid PCR

[0057] The microfluidic chip, such as Figure 1 As shown, the microfluidic chip includes: a microfluidic chip body and a chip cover; the microfluidic chip body has a groove, which forms a sample dispensing port 1, a reaction area 2, and a bubble collection groove 3; the bubble collection groove 3 includes a first connecting channel 31, a second connecting channel 32, and a bubble collection groove body 33.

[0058] The microfluidic chip body is made of plastic material. The chip cover is also made of plastic material.

[0059] The sample application port 1 is used to add the PCR reaction solution to the reaction area 2.

[0060] The reaction region 2 is used for the self-circulation of the PCR reaction solution, providing a site for PCR amplification; the reaction region 2 is divided into a high-temperature reaction region and a low-temperature reaction region, and the liquid flows under the influence of gravity and liquid temperature.

[0061] The bubble collection tank 3 is used to collect and store the bubbles generated by the PCR reaction solution in the reaction zone 2 during its self-circulation.

[0062] Example 2: A microfluidic chip device for rapid PCR

[0063] The microfluidic chip device includes: a microfluidic chip, a temperature control unit, a signal detection unit, and a data processing and control unit.

[0064] The temperature control unit comprises a heating assembly and a temperature sensor. The heating assembly includes 1-4 low-temperature zones and 1-4 high-temperature zones, which are alternately distributed. The temperature range of the low-temperature zones is 15-50℃, and the temperature range of the high-temperature zones is 65-150℃. The temperature sensor detects and outputs the temperature of reaction region 2. The temperature control unit is attached to the microfluidic chip body and is used to control the temperature of the microfluidic chip body, thereby changing the temperature of reaction region 2 within the microfluidic chip body.

[0065] The signal detection unit comprises an excitation light source, an optical transmission unit, and a photodetector; the signal detection unit is used to detect and output the fluorescence signal in the reaction region 2.

[0066] The data processing and control unit is used to process, store, and display the data output by the temperature control unit and the signal detection unit.

[0067] Example 3: Human Papillomavirus Nucleic Acid Detection Kit (PCR Fluorescent Probe Method)

[0068] (1) Take a cervical cell sample (52-year-old female sample) and transfer it to 1 mL / cell preservation solution. Centrifuge at 13,000 rpm for 10 minutes. Transfer 1 mL of the sample from the sterile sample tube to a 1.5 mL sterile centrifuge tube. After centrifugation, transfer 50 μL to another 1.5 mL sterile centrifuge tube, add 50 μL of nucleic acid release agent, mix thoroughly, and use it as a sample to be tested.

[0069] (2) Add 10 μL of sample, 38 μL of PCR reaction solution (human papillomavirus / type 16, 18), and 2 μL of enzyme mixture to the PCR reaction tube. The instrument used is a Stratagene Mx3000P real-time PCR instrument. The cycling parameters are set as follows: UNG enzyme reaction 50℃, 2 minutes / cycle, pre-denaturation 95℃, 10 minutes / cycle, denaturation 95℃, 10 seconds / 45 cycles, annealing extension 55℃, 45 seconds / 45 cycles. Select the FAM channel for detection. The Ct value is 33. The reported result is high-risk HPV negative (control group).

[0070] (3) 10 μL of sample, 38 μL of PCR reaction solution (human papillomavirus / types 16 and 18), and 2 μL of enzyme mixture were injected into reaction area 2 through sample port 1. PCR amplification was performed using four heating elements (H1: 95℃, H2: 75℃, L1: 50℃, L2: 40℃). Report fluorescence was performed using FAM with a Ct value of 35. The reported result was negative for high-risk HPV, consistent with the control group.

[0071] Example 4 verifies the design effectiveness of the heating module

[0072] This embodiment is based on TaqMan probe real-time fluorescence PCR technology. During the PCR reaction, the 5'→3' polymerase activity and exonuclease activity of Taq enzyme are simultaneously utilized to degrade the TaqMan probe, separating the fluorescent reporter group and quencher group, resulting in fluorescence signal emission. FAM fluorescence is used to detect hepatitis B virus, and the JOE / RED 610nm wavelength channel is used to detect the internal control. The PCR reaction solution contains 13μL of MgCl2 solution, 15μL of PCR buffer, 5μL of Taq enzyme, and 10μL of HBV primer probe. 7μL of quantitative quality control is added to the reaction tube, centrifuged at low speed for a few seconds, and then placed on the quantitative PCR instrument. The instrument used is an ABI 7500 dual-channel instrument: the reaction tube is first reacted at 50℃ for 2 minutes, then incubated at 94℃ for 5 minutes, and then cycled 40 times according to 94℃ / 10 ​​seconds → 60℃ / 45 seconds. The signals of the FAM and JOE fluorescence channels are acquired at 60℃. The software automatically calculates that the HBV DNA content is 7.2×10⁻⁶. 7 IU / mL (control group).

[0073] Experimental parameters: Three different heating modules were used.

[0074] Option 1: Use one H heating module ( Figure 2 The temperature was set to 95℃, and one L heating module was set to 40℃. After reacting for 30 minutes, the software automatically calculated that the HBV DNA content was 3.4 × 10⁻⁶. 7 IU / mL.

[0075] Option 2: Use 2 H heating modules ( Figure 3 The temperature was set at 95℃ / 85℃, with two L heating modules set at 60℃ / 50℃. After reacting for 30 minutes, the software automatically calculated that the HBV DNA content was 5.1×10⁻⁶. 7 IU / mL.

[0076] Option 3: Use 3 H heating modules ( Figure 4 The temperature was set to 95℃ / 85℃ / 75℃, and two L heating modules were set to 60℃ / 50℃ / 40℃. After reacting for 30 minutes, the software automatically calculated that the HBV DNA content was 7.4 × 10⁻⁶. 7 IU / mL.

[0077] Option 4: Use 4 H heating modules ( Figure 5 The reaction was performed at temperatures set to 95℃ / 90℃ / 85℃ / 80℃, with two L heating modules set at temperatures of 60℃ / 55℃ / 50℃ / 45℃. After 30 minutes of reaction, the software automatically calculated that the HBV DNA content was 3.2 × 10⁻⁶. 7IU / mL.

[0078] Option 5: Five H heating modules are used, with set temperatures of 95℃ / 90℃ / 85℃ / 80℃ / 75℃; two L heating modules are used, with set temperatures of 60℃ / 55℃ / 50℃ / 45℃ / 40℃. After reacting for 30 minutes, the software automatically calculates that the HBV DNA content is 1.8 × 10⁻⁶. 7 IU / mL.

[0079] The above results show that the present invention can shorten the reaction time while achieving the same detection efficiency. Furthermore, using multiple heating modules is more effective than using a single heating module; the amplification effect is best when there are three groups of heating modules. As the number of modules further increases, the amplification amount begins to decrease, indicating that the number of modules has a decisive influence on the amplification result.

[0080] Example 5: Design Utility of the Bubble Collection Tank

[0081] This embodiment is based on TaqMan probe real-time fluorescence PCR technology. During the PCR reaction, the 5'→3' polymerase activity and exonuclease activity of Taq enzyme are simultaneously utilized to degrade the TaqMan probe, separating the fluorescent reporter group and quencher group, resulting in fluorescence signal emission. FAM fluorescence is used to detect hepatitis B virus, and the JOE / RED 610nm wavelength channel is used to detect the internal control. The PCR reaction solution contains 13μL of MgCl2 solution, 15μL of PCR buffer, 5μL of Taq enzyme, and 10μL of HBV primer probe. 7μL of quantitative quality control is added to the reaction tube, centrifuged at low speed for a few seconds, and then placed on the quantitative PCR instrument. The instrument used is an ABI 7500 dual-channel instrument: the reaction tube is first reacted at 50℃ for 2 minutes, then incubated at 94℃ for 5 minutes, and then cycled 40 times according to 94℃ / 10 ​​seconds → 60℃ / 45 seconds. The signals of the FAM and JOE fluorescence channels are acquired at 60℃. The software automatically calculates that the HBV DNA content is 7.2*10 7 IU / mL (control group).

[0082] The experimental group used three H heating modules with set temperatures of 95℃ / 85℃ / 75℃ and two L heating modules with set temperatures of 60℃ / 50℃ / 40℃, with a reaction time of 30 minutes. The amplification capability of microfluidic chips with bubble collection channels of different shapes was investigated, with 10 parallel experiments performed for each scheme.

[0083] Option 1: Microfluidic chips such as Figure 1 As shown.

[0084] Option 2: Microfluidic chips such as Figure 6 As shown, the bubble collection groove is semi-circular and located on top of the microfluidic chip.

[0085] Option 3: Microfluidic chips, such as Figure 7 As shown, the bubble collection groove is square and located on top of the microfluidic chip.

[0086] Option 4: Microfluidic chips, such as Figure 8 As shown, the bubble collection groove is a hollow arc shape located on top of the microfluidic chip.

[0087] The results of amplification detection using microfluidic chips with bubble collection slots of different shapes are shown in Table 1.

[0088] Table 1

[0089] Type / Result Comparison Option 1 Option 2 Option 3 Option 4 DNA content (IU / mL) <![CDATA[7.2×10 7 ]]> <![CDATA[7.4×10 7 ]]> <![CDATA[2.1×10 7 ]]> <![CDATA[1.8×10 7 ]]> <![CDATA[1.4×10 7 ]]> RSD% 5.6％ 5.9 7.6 8.9 8.8

[0090] The above results show that the shape of the bubble collection groove described in this invention is more conducive to bubble collection and can increase the amplification rate. After changing the shape, the bubble collection capacity decreases, resulting in a decrease in the amplification rate. Therefore, the shape design of the bubble collection groove also plays a crucial role in microfluidic chips.

[0091] In summary, this invention provides a microfluidic chip for rapid PCR and its application. The microfluidic chip can significantly shorten the heating and cooling time, reduce the amount of reactant samples used, improve the analysis speed, and save detection costs, and has broad application prospects.

[0092] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A microfluidic chip for rapid PCR, characterized in that, The microfluidic chip includes: a microfluidic chip body and a chip cover; The microfluidic chip body has grooves, which form a sample dispensing port (1), a reaction area (2), and a bubble collection groove (3). The bubble collection tank (3) includes a first connecting channel (31), a second connecting channel (32), and a bubble collection tank body (33). The first connecting channel (31) and the second connecting channel (32) are parallel and symmetrical in structure. The width of the bubble collection tank body (33) is greater than that of the first connecting channel (31) and the second connecting channel (32). The bubble collection tank (3) is used to collect and store the bubbles generated by the PCR reaction solution in the reaction zone (2) during its own circulation; The reaction region (2) is used for the self-circulation of the PCR reaction solution, providing a site for PCR amplification.

2. The microfluidic chip for rapid PCR according to claim 1, characterized in that, The reaction region (2) is a circular groove structure.

3. The microfluidic chip for rapid PCR according to claim 1, characterized in that, The reaction zone (2) is divided into a high-temperature reaction zone and a low-temperature reaction zone, and the liquid flows under the influence of gravity and liquid temperature.

4. The microfluidic chip for rapid PCR according to claim 1, characterized in that, The microfluidic chip body is made of plastic; The chip cover is made of plastic.

5. The microfluidic chip for rapid PCR according to claim 1, characterized in that, The sample inlet (1) is used to add the PCR reaction solution to the reaction area (2).

6. A microfluidic chip device for rapid PCR, characterized in that, The microfluidic chip device comprises: a microfluidic chip for rapid PCR as described in any one of claims 1-5, a temperature control unit, a signal detection unit, and a data processing and control unit; The temperature control unit includes a heating component and a temperature sensor; The heating component includes 1-4 low-temperature zones and 1-4 high-temperature zones; the low-temperature zones and high-temperature zones are distributed alternately; the temperature range of the low-temperature zones is 15-50℃; the temperature range of the high-temperature zones is 65-150℃. The temperature sensor is used to detect and output the temperature of the reaction zone (2); The temperature control unit is attached to the microfluidic chip body. The temperature control unit is used to control the temperature of the microfluidic chip body and change the temperature of the reaction region (2) in the microfluidic chip body. The signal detection unit comprises an excitation light source, an optical transmission unit, and a photodetector; the signal detection unit is used to detect and output the fluorescence signal in the reaction region (2); The data processing and control unit is used to process, store, and display the data output by the temperature control unit and the signal detection unit.

7. A nucleic acid amplification method, characterized in that, include: Amplification was performed using the microfluidic chip device for rapid PCR as described in claim 6.

8. The nucleic acid amplification method according to claim 7, characterized in that, The steps of the nucleic acid amplification method include: (a) The PCR amplification reaction solution is injected into the microfluidic chip body through the sample dispensing port (1). The temperature control unit is used to control the temperature of the microfluidic chip body and change the temperature of the reaction area (2) in the microfluidic chip body. The PCR amplification reaction solution generates self-circulation in the reaction area (2) to achieve PCR amplification effect. The bubbles generated in the self-circulation enter the bubble collection tank (3). The signal detection unit is used to detect and output the fluorescence signal in the reaction area (2). (b) A data processing and control unit is used to process, store and display the data output by the signal detection unit.

9. The use of the microfluidic chip for rapid PCR according to any one of claims 1-5 and / or the microfluidic chip device for rapid PCR according to claim 6 in the preparation of PCR detection products.

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