CN213232279U

CN213232279U - Gas circuit system of PCR instrument

Info

Publication number: CN213232279U
Application number: CN202021803992.9U
Authority: CN
Inventors: 裴颢
Original assignee: Mezhuo Biotechnology Zhejiang Co ltd
Current assignee: Mezhuo Biotechnology Zhejiang Co ltd
Priority date: 2020-08-25
Filing date: 2020-08-25
Publication date: 2021-05-18
Anticipated expiration: 2030-08-25

Abstract

The utility model relates to a gas circuit system of a PCR instrument, which comprises a machine body and a control circuit, wherein a push table component is arranged in the machine body, a plurality of nozzles are arranged at the bottom of the push table component, an air pump is also arranged in the machine body, the gas outlet of the air pump is respectively connected with a liquid storage container and a gas pipe through a pressure controller, and the liquid storage container and the gas pipe are respectively connected with the nozzles; the air pump and the pressure controller are respectively electrically connected with the control circuit. The air pump in the air path system of the PCR instrument is arranged in the PCR instrument, so that the PCR instrument is provided with an air source, is convenient to carry and is suitable for being used in various occasions; the air supply can provide power for the sample to be tested, and in addition, the air supply is communicated with the liquid storage container and can provide pressure for liquid (isolation oil and separation oil) injected into the microfluidic chip, so that the liquid can smoothly enter the internal microchannel of the microfluidic chip.

Description

Gas circuit system of PCR instrument

Technical Field

The utility model relates to a PCR appearance, especially a gas circuit system of PCR appearance.

Background

Polymerase Chain Reaction (PCR) is a molecular biology technique for amplifying and amplifying specific DNA fragments, and can be regarded as special DNA replication in vitro, and the greatest feature of PCR is that a trace amount of DNA can be greatly increased.

In the PCR, DNA is denatured at a high temperature of 95 ℃ in vitro to become a single strand, a primer and the single strand are combined according to the principle of base complementary pairing at a low temperature (usually about 60 ℃), the temperature is adjusted to the optimal reaction temperature (about 72 ℃) of DNA polymerase, and the DNA polymerase synthesizes a complementary strand along the direction from phosphate to pentose.

The basic principle of current digital PCR analysis is to distribute a sample into a large number of droplets, each droplet containing one or more samples to be tested, then perform PCR amplification on the samples to be tested, and analyze the droplets after PCR amplification. In the analysis process, the sample to be detected has no fluidity, PCR amplification is realized by repeatedly switching the heating temperature of the sample to be detected, and the PCR amplification efficiency is low because the waiting process is long when the heating temperature is repeatedly changed in the process. Therefore, it is necessary to consider that the sample to be detected is changed into flowable, and the heating module can be changed into one with high-temperature and low-temperature double-temperature heating, so that the sample to be detected flows between different heating temperature regions, and the PCR amplification efficiency of the sample to be detected is accelerated. However, there is currently no good way of constructing a structure that allows the sample to be measured to flow.

Disclosure of Invention

An object of the utility model is to provide a rational in infrastructure, through the mobile gas circuit system of PCR appearance of the sample that awaits measuring of atmospheric pressure control.

The purpose of the utility model is realized like this:

the utility model provides a gas circuit system of PCR appearance, includes organism and control circuit, is equipped with in the organism and pushes away a subassembly, and the bottom that pushes away a subassembly is equipped with a plurality of mouths head, its characterized in that: an air pump is further arranged in the machine body, an air outlet of the air pump is respectively connected with the liquid storage container and the air pipe through a pressure controller, and the liquid storage container and the air pipe are respectively connected with the nozzle; the air pump and the pressure controller are respectively electrically connected with the control circuit.

The purpose of the utility model can also adopt the following technical measures to solve:

as a more specific scheme, a dryer, a buffer gas cylinder and a first safety valve are further sequentially arranged between the gas outlet of the gas pump and the pressure controller.

The opening pressure of the first safety valve is 0.5 Mpa.

The pressure controller is provided with an input port and three output channels, the input port is connected with the safety valve, the three output channels are respectively a first channel, a second channel and a third channel, the liquid storage container comprises a first liquid storage bottle, a second liquid storage bottle and a waste liquid bottle, and the first channel, the second channel and the third channel are respectively connected with the first liquid storage bottle, the second liquid storage bottle and a gas pipe; the push table component is provided with four nozzle heads, and each nozzle head is respectively communicated with the first liquid storage bottle, the second liquid storage bottle, the waste liquid bottle and the air pipe through the pipe body.

The air pump is communicated with the outside of the machine body through a filter.

The buffer gas cylinder is further connected with a pressure release valve, and the pressure release valve is electrically connected with the control circuit.

The air pump is a micro piston pump, and the air pressure output by an air outlet of the micro piston pump is greater than 0.5 Mpa.

The push table component comprises a mounting table and an air cylinder used for pushing the mounting table, the nozzle head is arranged at the bottom of the mounting table, the air cylinder is connected with the buffer air bottle through an electromagnetic steering valve and a second safety valve, and the electromagnetic steering valve is electrically connected with the control circuit.

Four Ruhr joints are distributed on the mounting table in a rectangular mode, each Ruhr joint is connected with a pipe body, the lower end of each Ruhr joint extends out of the bottom surface of the mounting table, the lower end of each Ruhr joint is provided with the nozzle head, the nozzle head is provided with a through hole, and the through holes are communicated with the pipe bodies.

The opening pressure of the second safety valve is 0.2 Mpa.

The utility model has the advantages as follows:

the air pump in the air path system of the PCR instrument is arranged in the PCR instrument, so that the PCR instrument is provided with an air source, is convenient to carry and is suitable for being used in various occasions; the air supply can provide power for the sample to be tested, and in addition, the air supply is communicated with the liquid storage container and can provide pressure for liquid (isolation oil and separation oil) injected into the microfluidic chip, so that the liquid can smoothly enter the internal microchannel of the microfluidic chip.

Drawings

Fig. 1 is a block diagram of an embodiment of the present invention.

Fig. 2 is an exploded schematic view of an embodiment of the present invention.

Fig. 3 is a schematic view of the connection structure of the heating module and the fixing base of the present invention.

Fig. 4 is another angle structure diagram of fig. 3.

Fig. 5 is the exploded structure diagram of the heating module and the fixing base of the present invention.

Fig. 6 is another angle structure diagram of fig. 5.

FIG. 7 is a schematic structural view of the extension state (to be loaded with the microfluidic chip) of the stage assembly of the PCR apparatus of the present invention.

FIG. 8 is a schematic structural view of the stage assembly of the PCR apparatus of the present invention in a retracted state (loading the microfluidic chip).

Fig. 9 is a schematic view of an exploded structure of a microfluidic chip used in cooperation with the present invention.

Fig. 10 is a schematic top view of fig. 9.

FIG. 11 is a schematic sectional view A-A of FIG. 10.

Fig. 12 is a schematic sectional structure view of B-B of fig. 10.

Fig. 13 is an enlarged view of the structure at F in fig. 12.

Fig. 14 is a schematic cross-sectional structure view of C-C of fig. 10.

Fig. 15 is an enlarged schematic view of G in fig. 14.

Fig. 16 is a schematic sectional view of fig. 10 taken along line D-D.

FIG. 17 is a schematic cross-sectional view of E-E of FIG. 10.

Fig. 18 is an exploded view of the middle support platform assembly of the present invention.

Fig. 19 is another angle structure diagram of fig. 18.

Fig. 20 is a schematic perspective view of the middle pushing platform assembly of the present invention.

Fig. 21 is an exploded view of the middle pushing platform assembly of the present invention.

Fig. 22 is another angle structure diagram of fig. 21.

Fig. 23 is a schematic top view of fig. 22.

FIG. 24 is a schematic sectional view of the structure of FIG. 23 taken in section H-H.

Fig. 25 is an enlarged schematic view of the structure at I in fig. 24.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and examples.

Referring to fig. 1 to 25, an air path system of a PCR instrument includes a base assembly (including a fixing base 6 and a bottom plate 40), a platform assembly 30 for placing a microfluidic chip 5, a platform driving mechanism, a platform pushing assembly 10 for injecting liquid into the microfluidic chip 5, a heating module 20 for heating the microfluidic chip 5, a fluorescence detection module for determining an image of a droplet reaction unit on the microfluidic chip 5, a liquid storage container, and an air source. The heating module 20 is arranged on the base assembly, the bearing platform assembly 30 is transversely arranged on the base assembly in a sliding mode, the bearing platform assembly 30 is further provided with a chip bearing platform 7 which moves up and down, the chip bearing platform 7 is located above the heating module 20, the pushing platform assembly 10 is arranged above the bearing platform assembly 30 and is opposite to the heating module 20, the bottom of the pushing platform assembly 10 is provided with a plurality of nozzles 143, the nozzles 143 are respectively connected with a liquid storage container and a gas source, the fluorescence detection module is arranged below the heating module 20, the heating module 20 is provided with light transmitting holes corresponding to the fluorescence detection module, the light transmitting holes penetrate through the upper side and the lower side of the heating module 20, the heating module 20 is provided with at least two heating zones, and a heat insulation belt is arranged between each heating zone.

The method comprises the following steps: the heating module 20 comprises two metal heat conduction blocks, namely a first metal heat conduction block 201 and a second metal heat conduction block 202; the heating module 20 further includes a heat insulation frame 204, the heat insulation frame 204 is provided with a first embedded hole 2011 and a second embedded hole 2021 corresponding to the first metal heat conduction block 201 and the second metal heat conduction block 202, the embedded holes are separated from each other (the separated part forms the heat insulation belt), the first metal heat conduction block 201 and the second metal heat conduction block 202 are embedded in the first embedded hole 2011 and the second embedded hole 2021, respectively, and top surfaces of the first metal heat conduction block 201 and the second metal heat conduction block 202 are exposed out of a top surface of the heat insulation frame 204.

The metal heat conducting block is a copper block, a thick film heating body is arranged at the bottom of the copper block, a heating area is formed on the top surface of each copper block, and the heat insulation frame 204 is made of bakelite.

The heat insulation frame 204 is provided with a first light hole 203 corresponding to a space between the first metal heat conduction block 201 and the second metal heat conduction block 202.

The heating module 20 further includes a heat insulation bottom cover 206, the bottom of the heat insulation frame 204 is provided with a sinking groove 207 corresponding to the heat insulation bottom cover 206, the sinking groove 207 is communicated with the embedding hole, the heat insulation bottom cover 206 is arranged in the sinking groove 207 and connected with the metal heat conduction block, the heat insulation bottom cover 206 is provided with a second light hole 2064 corresponding to the first light hole 203, and the heat insulation bottom cover 206 is provided with a first threading hole 2063 corresponding to the metal heat conduction block.

Heating module 20 sets up on fixing base 6, and fixing base 6 top surface corresponds heating module 20 and is equipped with constant head tank 61, and the inner wall of constant head tank 61 is equipped with location platform 62, the chip reference column sets up on location platform 62, in heating module 20 embedding constant head tank 61, the thermal-insulated frame 204 outer wall of heating module 20 corresponds location platform 62 and is equipped with location bayonet 205, and location bayonet 205 is pegged graft with location platform 62. The bottom of constant head tank 61 corresponds first through wires hole 2063 and is equipped with second through wires hole 64, and the bottom of constant head tank 61 corresponds second light trap 2064 and is equipped with third light trap 65.

The fixing seat 6 is arranged on the bottom plate 40, the pushing assembly 10 is further arranged above the fixing seat 6, the pushing assembly 10 comprises an installation table 4 and a driving device used for pushing the installation table 4, a nozzle 143 is arranged on the bottom surface of the installation table 4, the nozzle 143 is communicated with the tube body 2, more than two chip positioning columns 63 are arranged on the fixing seat 6, the chip positioning columns 63 are used for being in inserting fit with the positioning holes 53 of the microfluidic chip 5, nozzle holes 56 are formed in the microfluidic chip 5, and when the positioning holes 53 on the microfluidic chip 5 are sleeved with the chip positioning columns 63 in a one-to-one correspondence mode, the nozzle holes 56 are opposite to the nozzle 143.

Four Ruhr connectors 1 are distributed on the mounting table 4 in a rectangular mode, each Ruhr connector 1 is connected with the pipe body 2, the lower end of each Ruhr connector 1 extends out of the bottom surface of the mounting table 4, the nozzle 143 is arranged at the lower end of each Ruhr connector 1, a through hole is formed in the nozzle 143, and the through hole is communicated with the pipe body 2.

The luer connector 1 comprises a male connector 11, a female connector 14 and a soft sleeve 13, wherein the center of the male connector 11 is provided with a plug tube hole 111 penetrating through two ends of the male connector, the female connector 14 is provided with a stepped hole 141, the stepped hole 141 is communicated with a through hole 146 of a nozzle 143, a soft sleeve limiting step 144 and a tube limiting step 145 which are distributed up and down are arranged in the stepped hole 141, and the tube limiting step 145 is positioned above the through hole 146; the soft sleeve 13 is arranged on the soft sleeve limiting step 144, and the tube body 2 penetrates through the insertion tube hole 111 and the soft sleeve 13 and then is inserted into the tube limiting step 145; the mounting table 4 is provided with a connector mounting hole 41 corresponding to the female connector 14, the female connector 14 is inserted into the connector mounting hole 41 and is fixedly connected with the mounting table 4, the lower end of the male connector 11 is inserted into the stepped hole 141 and is in threaded connection with the stepped hole 141, and the soft sleeve 13 is tightly pressed between the lower end of the male connector 11 and the soft sleeve limiting step 144.

The joint mounting hole 41 penetrates through the upper end and the lower end of the mounting table 4, the outer end of the female joint 14 is also provided with a cushion surface 142, the outer diameter of the cushion surface 142 is larger than that of the female joint 14, and the nozzle 143 protrudes out of the bottom surface of the cushion surface 142; the upper end of the female terminal 14 is inserted into the terminal mounting hole 41 from below to above and protrudes onto the top surface of the mounting table 4, and the upper end of the female terminal 14 is connected to the lock nut 12.

The periphery of the upper end of the male connector 11 is provided with anti-skid grains 112.

Four Ruhr joints 1 are distributed on the mounting table 4 in a rectangular mode, and each Ruhr joint 1 is connected with a pipe body 2.

The driving device comprises a cylinder 3, and the outer end of a piston rod 31 of the cylinder 3 is in transmission connection with the mounting table 4.

The outer end of the piston rod 31 is connected with a flange 32, and the flange 32 is connected with the top surface of the mounting table 4.

The base plate 40 is provided with a bearing platform assembly 30, the bearing platform assembly 30 is connected with the base plate 40 through a linear guide rail 8, a bearing platform driving mechanism 9 is arranged between the bearing platform assembly 30 and the base plate 40, and the bearing platform driving mechanism 9 is arranged on the base plate 40 and is in transmission connection with the bearing platform assembly 30. The bearing platform assembly 30 comprises a chip bearing platform 7, and an elastic part is arranged between the chip bearing platform 7 and the linear guide rail 8. The chip bearing table 7 is arranged between the fixed seat 6 and the pushing table assembly 10, and the chip bearing table 7 is provided with a second positioning hole 72 corresponding to the chip positioning column 63; the chip bearing platform 7 is provided with a sinking platform for placing the microfluidic chip 5, the sinking platform is provided with an opening 73 corresponding to the heating module 20, the edge of the opening 73 is provided with a supporting convex edge 71, and the second positioning hole 72 is arranged on the supporting convex edge 71.

The micro-fluidic chip 5 and the supporting flange 71 are respectively provided with three first positioning holes 53 and three second positioning holes 72, and the three first positioning holes 53 and the three second positioning holes 72 are mutually corresponding and are distributed in a triangular shape. An orientation protrusion 731 is arranged in the sinking platform, an orientation groove 54 is arranged on the micro-fluidic chip 5 corresponding to the orientation protrusion 731, and the orientation groove 54 is in positioning, inserting and matching with the orientation protrusion 731.

The fixing base 6 is provided with three chip positioning columns 63, and the three chip positioning columns 63 are in inserting fit with the first positioning hole 53 and the second positioning hole 72. The top end of the chip positioning column 63 is provided with a conical head 631 with a narrow top and a wide bottom. The surface of the conical head is provided with an inclined plane which has a certain guiding function.

The micro-fluidic chip 5 is provided with two liquid injection ports, one gas inlet and one liquid outlet, wherein the liquid injection ports, the gas inlet and the liquid outlet (56 marked in the reference figure 8) are sleeved with silica gel cups 51, the silica gel cups 51 are provided with nozzle holes 52, and the silica gel cups 51 are connected into a whole through silica gel gaskets 511.

The bearing platform assembly 30 further comprises an elastic supporting device, the elastic supporting device comprises a supporting rod 77, the elastic part and a fixing groove 79, the supporting rod 77 is connected to the bottom of the chip bearing platform 7, and first limiting flanges 771 are arranged on two sides of the bottom of the supporting rod 77; fixed slot 79 is connected with linear guide 8, the fixed slot 79 top surface is equipped with fluting 791, the opening inboard of fluting 791 is equipped with the spacing turn-ups 793 of second, 77 lower parts of the support rod insert in the fluting 791, and with fluting 791 about sliding fit, first spacing turn-ups 771 keeps off with the spacing turn-ups 793 of second mutually, the elastic component is equipped with a plurality ofly, and along 77 length direction straight line distributions of support rod, the elastic component sets up between the bottom surface of support rod 77 and the fluting 791 bottom surface of fixed slot 79.

The inner wall of the second limiting flange 793 of the fixing groove 79 is provided with an antifriction convex rib 792.

The elastic supporting devices are provided with a left set and a right set, and one elastic supporting device of each set is arranged at the bottom of the chip bearing platform 7 from left to right; the elastic member is a spring 78, a positioning cavity 772 is formed at the bottom of the support rod 77 corresponding to the spring 78, and the upper end of the spring 78 is inserted into the positioning cavity 772.

The bearing platform assembly 30 further comprises a side plate 75 and a panel 74, wherein the outer side of the fixing groove 79 is connected with the side plate 75, and the front end of the fixing groove 79 is connected with the panel 74; the top end of the side plate 75 is provided with an inward flange 751, the left and right sides of the chip platform 7 are provided with outward flanges 76, and the top surfaces of the outward flanges 76 are blocked with the bottom surfaces of the inward flanges 751.

The cap assembly 30 further includes an end cap 710 disposed at a rear end of the fixing groove 79.

The linear guide rail 8 comprises a fixed block 81, a guide roller 82 and a slide rail 83, the fixed block 81 is fixedly connected with the bottom plate 40, the guide roller 82 is horizontally arranged on the fixed block 81 in a rotating mode, an annular groove 821 is arranged on the periphery of the guide roller 82, a guide groove is formed in the bottom of the slide rail 83, a guide convex rib 831 matched with the annular groove 821 is arranged on the inner wall of the guide groove, and the slide rail 83 is connected with the fixed groove 79.

The bearing platform driving mechanism 9 is a screw rod driving mechanism, the screw rod driving mechanism comprises a driving motor 91, a nut 92, a screw rod 93, a guide seat 94 and a connecting lug 95, the guide seat 94 is arranged on the bottom plate 40, the top surface of the guide seat 94 is a plane, the bottom surface of the nut 92 is a plane and is in sliding fit with the top surface of the guide seat 94, the connecting lug 95 is connected between the nut 92 and the side plate 75 of the bearing platform assembly 30, baffle plates are arranged at the front end and the rear end of the guide seat 94, the screw rod 93 is in threaded connection with the nut 92 and is rotatably arranged between the two baffle plates, and the driving motor 91 is arranged outside one baffle plate and is in transmission connection with the screw rod 93.

The fixing seat 6 is arched, the fluorescence detection module is arranged at the bottom of the fixing seat 6, and the fluorescence detection module detects the microfluidic chip through the first light-transmitting hole, the second light-transmitting hole and the third light-transmitting hole. The fluorescence detection module comprises a filter group, a PMT (photomultiplier tube) and a laser, wherein the PMT (photomultiplier tube) is electrically connected with the control circuit through the acquisition board, and the laser is electrically connected with the control circuit.

The air source is an air pump disposed on the base plate 40. The air outlet of the air pump is respectively connected with the liquid storage container and the air pipe through the pressure controller, and the liquid storage container and the air pipe are respectively connected with the nozzle 143; the air pump and the pressure controller are respectively electrically connected with the control circuit.

And a dryer, a buffer gas cylinder and a first safety valve are sequentially arranged between the gas outlet of the gas pump and the pressure controller.

The opening pressure of the first safety valve is 0.5 Mpa.

The pressure controller is provided with an input port and three output channels, the input port is connected with the safety valve, the three output channels are respectively a first channel, a second channel and a third channel, the liquid storage container comprises a first liquid storage bottle, a second liquid storage bottle and a waste liquid bottle, and the first channel, the second channel and the third channel are respectively connected with the first liquid storage bottle, the second liquid storage bottle and a gas pipe; the four nozzles 143 of the push table assembly 10 are respectively communicated with the first liquid storage bottle, the second liquid storage bottle, the waste liquid bottle and the air pipe through the pipe body 2.

The air cylinder 3 of the push table assembly 10 is connected with the buffer air cylinder through an electromagnetic steering valve and a second safety valve, and the electromagnetic steering valve is electrically connected with the control circuit.

The opening pressure of the second safety valve is 0.2 Mpa.

The control circuit is also electrically connected with a power supply, a display and control terminal and a data transmission port.

The working principle is as follows: the bearing platform assembly 30 extends forwards, the orientation groove 54 of the microfluidic chip 5 is aligned with the orientation protrusion 731 of the chip bearing platform 7 and then placed into the sinking platform of the chip bearing platform 7, the bearing platform assembly 30 moves backwards between the fixed seat 6 and the push platform assembly 10 under the control of the bearing platform driving mechanism 9, and the second positioning hole 72 of the chip bearing platform 7 is opposite to the center of the chip positioning column 63 of the fixed seat 6. When the mounting table 4 of the push table assembly 10 moves downwards, the microfluidic chip 5 and the chip bearing table 7 are pushed to move downwards at the same time, when the second positioning hole 72 of the chip bearing table 7 and the positioning hole 53 of the microfluidic chip 5 are in contact with the conical head 631 of the chip positioning column 63, the conical head 631 guides the second positioning hole 72, the positioning hole 53 and the chip positioning column 63 to be concentric, so that the bearing table assembly 30, the microfluidic chip 5, the push table assembly 10 and the heating module 20 are positioned completely, the nozzle 143 of the luer 1 of the push table assembly 10 is ensured to be inserted into the nozzle hole 52 of the microfluidic chip 5, the pad surface 142 of the luer 1 is in sealing fit with the silicone rubber cup 51 of the microfluidic chip 5, and operations such as liquid injection and gas supply can be performed at the moment without leakage.

Because the micro-fluidic chip 5 is internally provided with an S-shaped micro-fluidic channel, a test sample is injected into the channel; one part of the microfluidic channel is positioned on the top surface of the first metal heat-conducting block 201, and the other part of the microfluidic channel is positioned on the top surface of the second metal heat-conducting block 202; the first metal heat-conducting block 201 and the second metal heat-conducting block 202 are heated to required temperatures by electric heaters respectively, and the test sample repeatedly passes through the top surface of the first metal heat-conducting block 201 and the top surface of the second metal heat-conducting block 202 by controlling the flow of the test sample in the microfluidic channel, so that the test sample is repeatedly subjected to thermal cycle until a sufficient copy number for analysis is obtained.

When the micro-fluidic chip 5 is subjected to thermal cycle treatment, the micro-fluidic chip 5 is pressed and positioned on the heating module 20 by the push table assembly 10, so that on one hand, the micro-fluidic chip 5 is attached to the heating module 20, the heat loss is reduced, and more accurate heat transfer is obtained; on the other hand, the nozzle 143 of the push platform assembly 10 is positioned and matched with the nozzle hole 56 of the microfluidic chip 5, so that the tightness of the tube body 2 in the air and liquid infusion process is ensured.

Claims

1. The utility model provides a gas circuit system of PCR appearance, includes organism and control circuit, is equipped with in the organism and pushes away a subassembly (10), and the bottom that pushes away a subassembly (10) is equipped with a plurality of nozzles (143), its characterized in that: an air pump is further arranged in the machine body, an air outlet of the air pump is respectively connected with a liquid storage container and an air pipe through a pressure controller, and the liquid storage container and the air pipe are respectively connected with a nozzle (143); the air pump and the pressure controller are respectively electrically connected with the control circuit.

2. The air circuit system of the PCR instrument of claim 1, wherein: and a dryer, a buffer gas cylinder and a first safety valve are sequentially arranged between the gas outlet of the gas pump and the pressure controller.

3. The air circuit system of the PCR instrument of claim 2, wherein: the opening pressure of the first safety valve is 0.5 Mpa.

4. The air circuit system of the PCR instrument of claim 2, wherein: the pressure controller is provided with an input port and three output channels, the input port is connected with the safety valve, the three output channels are respectively a first channel, a second channel and a third channel, the liquid storage container comprises a first liquid storage bottle, a second liquid storage bottle and a waste liquid bottle, and the first channel, the second channel and the third channel are respectively connected with the first liquid storage bottle, the second liquid storage bottle and a gas pipe; the push table component (10) is provided with four nozzle heads (143), and each nozzle head (143) is respectively communicated with the first liquid storage bottle, the second liquid storage bottle, the waste liquid bottle and the air pipe through the pipe body (2).

5. The air circuit system of the PCR instrument of claim 1, wherein: the air pump is communicated with the outside of the machine body through a filter.

6. The air circuit system of the PCR instrument of claim 2, wherein: the buffer gas cylinder is further connected with a pressure release valve, and the pressure release valve is electrically connected with the control circuit.

7. The air circuit system of the PCR instrument of claim 1, wherein: the air pump is a micro piston pump, and the air pressure output by an air outlet of the micro piston pump is greater than 0.5 Mpa.

8. The air circuit system of the PCR instrument of claim 2, wherein: the push bench component (10) comprises a mounting bench (4) and a cylinder (3) used for pushing the mounting bench (4), the nozzle head (143) is arranged at the bottom of the mounting bench (4), the cylinder (3) is connected with a buffer gas cylinder through an electromagnetic steering valve and a second safety valve, and the electromagnetic steering valve is electrically connected with a control circuit.

9. The air circuit system of the PCR instrument of claim 8, wherein: four luer connectors (1) are distributed on the mounting table (4) in a rectangular mode, each luer connector (1) is connected with a pipe body (2), the lower end of each luer connector (1) extends out of the bottom face of the mounting table (4), the lower end of each luer connector (1) is provided with the nozzle head (143), the nozzle head (143) is provided with a through hole (146), and the through hole (146) is communicated with the pipe body (2).

10. The air circuit system of the PCR instrument of claim 8, wherein: the opening pressure of the second safety valve is 0.2 Mpa.