A fluid control chip

Abstract

The present invention provides a fluid control chip, which relates to the technical field of biomacromolecule purification, including a chip, a solution inlet, a waste liquid outlet, and a negative pressure port are provided on the chip, an adsorption flow channel and a premixing chamber are provided in the chip; a filler capable of adsorbing biomacromolecules is preset in the adsorption flow channel; the solution inlet is connected to the adsorption flow channel, and the adsorption flow channel is connected to the waste liquid outlet and the premixing chamber; the negative pressure port is connected to the premixing chamber; the first solution, the second solution and the third solution are sequentially introduced from the solution inlet; the waste liquid outlet is used to draw negative pressure and drive the first solution and the second solution to be discharged after passing through the adsorption flow channel; the negative pressure port is used to draw negative pressure and drive the third solution to flow into the premixing chamber, and biomacromolecules are collected in the premixing chamber. The microfluidic chip provided by the present invention can make the flow of various liquids in the chip well controllable, and various liquids are not easy to contaminate each other, so that the purity of the purified biomacromolecules is high, which is convenient for subsequent further analysis.

Description

Technical Field

[0001] The present invention relates to the technical field of biomacromolecule purification, and in particular to a fluid control chip. Background Art

[0002] Microfluidics, also known as microfluidic chip technology, can integrate basic operating units such as sample preparation, reaction, separation, and detection in biological, chemical, and medical analysis processes onto a chip of several centimeters. Controllable fluids run through the entire system to replace various functions of conventional chemical or biological laboratories. It has the advantages of light size, small amount of samples and reagents, low energy consumption, fast reaction speed, low cost, large-scale parallel processing, and disposable. At present, microfluidic chips are widely used in the field of microbial detection.

[0003] Most of the liquid flow power in the existing microfluidic chips comes from centrifugal force and the capillary action of the pipeline, such as the Chinese utility model patent with application number 202121770101.9; there is also a product that uses pressure to drive the movement of fluid, such as the Chinese invention patent application with application number 201911328740.7. However, whether it is centrifugal drive or pressure drive, the two methods have poor controllability, and the above two existing technologies pre-set the liquid other than the sampling liquid in the chip. Although it meets the purpose of taking and using, it is easy to cause the liquid to flow in the chip during the transfer process. When using such chips to purify biological macromolecules such as nucleic acids and proteins, the purity of the purified biological macromolecules such as nucleic acids or proteins is often not high and contains a large amount of impurities. A large amount of impurities will affect the subsequent further analysis of biological macromolecules such as nucleic acids or proteins, and it is impossible to conduct in-depth research and analysis on the purified products, and even obtain wrong experimental results, which ultimately leads to chip failure. Based on this, a new solution is urgently needed to solve the above problems. Summary of the invention

[0004] The purpose of the present invention is to provide a fluid control chip to solve the problems existing in the above-mentioned prior art. The flow of various liquids in the chip is well controllable and the various liquids are not easily contaminated with each other.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a fluid control chip, comprising a chip, wherein a solution inlet, a waste liquid outlet, and a negative pressure port are provided on the chip, an adsorption flow channel and a premixing chamber are provided in the chip; a filler capable of adsorbing biomacromolecules is preset in the adsorption flow channel; the solution inlet is connected to the adsorption flow channel, and the adsorption flow channel is connected to the waste liquid outlet and the premixing chamber; the negative pressure port is connected to the premixing chamber; a first solution, a second solution, and a third solution are sequentially introduced from the solution inlet; the waste liquid outlet is used for pumping negative pressure and for driving the first solution and the second solution to be discharged after passing through the adsorption flow channel; the negative pressure port is used for pumping negative pressure and driving the third solution to flow into the premixing chamber, and the biomacromolecules are collected in the premixing chamber.

[0007] Preferably, there are three solution inlets, namely, a first solution inlet, a second solution inlet and a third solution inlet, the second solution inlet is arranged at the front end of the first solution inlet, the first solution inlet and the second solution inlet are connected in series and communicated with the adsorption channel through the second flow channel, the third solution inlet is communicated with the adsorption channel through the third flow channel, the second flow channel and the third flow channel intersect and are connected at the end of the adsorption channel, an overflow prevention chamber is arranged at the intersection of the second flow channel and the third flow channel, and the second flow channel and the third flow channel are respectively connected to the two ends of the top of the overflow prevention chamber.

[0008] Preferably, the second flow channel and the third flow channel are both in the shape of a "U-shape" plus an "inverted U-shape" and are interconnected, and the tops of both ends of the top of the overflow prevention chamber are connected to the "inverted U-shape" part.

[0009] Preferably, the place where the anti-overflow chamber is connected to the third flow channel is expanded.

[0010] Preferably, the chip is also provided with an air vent which can be closed or opened during operation, and the air vent is connected to the bottom of the premixing chamber; the air vent is connected to the bottom of the premixing chamber through a first flow channel and a fourth flow channel, the first flow channel is connected to the fourth flow channel, the first flow channel is connected to the bottom of the premixing chamber, the fourth flow channel is connected to the air vent, and the inner diameter of the fourth flow channel is smaller than the inner diameter of the first flow channel.

[0011] Preferably, at least part of the first flow channel is a reciprocating bending flow channel.

[0012] Preferably, the chip further comprises a product outlet, and the product outlet is connected to both the first flow channel and the fourth flow channel.

[0013] Preferably, the negative pressure port is communicated with the top of the premixing chamber, and a liquid baffle is fixedly provided below the negative pressure port.

[0014] Preferably, the chip includes a chip body and a transparent covering film, the adsorption channel and the premixing chamber are arranged on the front side of the chip body, the solution inlet, the waste liquid outlet and the negative pressure port are opened on the back side, and the covering film is covered on the front side of the chip body and can close the adsorption channel and the premixing chamber.

[0015] Preferably, the biomacromolecule is a nucleic acid or a protein.

[0016] Compared with the prior art, the present invention has achieved the following technical effects:

[0017] The microfluidic chip provided by the present invention drives the liquid to flow in the corresponding flow channels and chambers in the chip by drawing negative pressure, abandoning the existing centrifugal drive and pressure drive methods, and improving the controllability of liquid flow. When the scheme provided by the present invention is used to purify biological macromolecules, various solutions are stored separately and do not need to be preset in the chip for storage, so there is no problem of liquid cross-flow. Therefore, the microfluidic chip provided by the present invention makes the flow of various liquids in the chip well controllable, and the various liquids are not easy to contaminate each other, so that the biological macromolecules obtained after purification have high purity, which is convenient for subsequent further analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A schematic diagram of the structure of the microfluidic chip provided in Example 1;

[0020] Figure 2 A schematic diagram of the structure of the microfluidic chip provided in Example 3;

[0021] In the figure: 1-chip body; 2-waste liquid outlet; 3-negative pressure port; 4-adsorption flow channel; 5-premixing chamber; 6-first solution inlet; 7-second solution inlet; 8-third solution inlet; 9-second flow channel; 10-third flow channel; 11-anti-overflow chamber; 12-air vent; 13-first flow channel; 14-fourth flow channel; 15-liquid baffle; 16-fourth solution inlet; 17-product outlet. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] The purpose of the present invention is to provide a fluid control chip to solve the problems existing in the above-mentioned prior art. The flow of various liquids in the chip is well controllable and the liquids are not easily contaminated with each other.

[0024] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. Example

[0025] This embodiment provides a fluid control chip, such as Figure 1 As shown, it includes a chip 1, on which a solution inlet, a waste liquid outlet 2 and a negative pressure port 3 are provided, and an adsorption channel 4 and a premixing chamber 5 are provided inside the chip 1; a filler capable of adsorbing biological macromolecules is preset in the adsorption channel 4; the solution inlet is connected to the adsorption channel 4, and the adsorption channel 4 is connected to the waste liquid outlet 2 and the premixing chamber 5; the negative pressure port 3 is connected to the premixing chamber 5; the first solution, the second solution and the third solution are introduced in sequence from the solution inlet; the waste liquid outlet 2 is used to draw negative pressure and drive the first solution and the second solution to be discharged after passing through the adsorption channel; the negative pressure port 3 is used to draw negative pressure and drive the third solution to flow into the premixing chamber 5, and the biological macromolecules are collected in the premixing chamber 5.

[0026] Among them, the microfluidic chip provided in this embodiment is used for purifying nucleic acids, and the filler in the adsorption channel 4 can be silica gel membrane, acid-washed glass beads, large adsorption magnetic beads, etc. In order to simplify the structure, the filler in the adsorption channel 4 is preferably silica gel membrane.

[0027] To this end, in this embodiment, the first solution is a lysed bacterial sample containing nucleic acid; the second solution is a cleaning solution, and in order to facilitate the volatilization of the cleaning solution, the cleaning solution is preferably ethanol; the third solution is an eluent, and in order to elute the nucleic acid on the silica gel membrane into the premixing chamber 5, the eluent is preferably ultrapure water.

[0028] Furthermore, both the waste liquid outlet 2 and the negative pressure port 3 can be connected to a negative pressure pumping device. In order to simplify the device, the driving pump in this embodiment is preferably a negative pressure pumping device.

[0029] When using the microfluidic chip provided in this embodiment to purify nucleic acid, first, draw negative pressure at the waste liquid outlet 2, pass the lysed bacterial sample, the lysed bacterial sample flows out from the waste liquid outlet 2 after passing through the adsorption flow channel 4 under the action of negative pressure, and the nucleic acid in the lysed bacterial sample is adsorbed by the silica gel membrane; secondly, draw negative pressure at the waste liquid outlet 2, pass ethanol, ethanol flows out from the waste liquid outlet 2 after passing through the adsorption flow channel 4 under the action of negative pressure, the silica gel membrane and the impurities thereon are cleaned by the cleaning liquid, and the nucleic acid is retained on the silica gel membrane. After the cleaning liquid is discharged, the solution inlet is connected to the atmosphere, and the negative pressure is continuously drawn to dry the ethanol residue on the silica gel membrane and the flow channel. After the silica gel membrane is dried, the solution inlet is closed. Finally, draw negative pressure at the negative pressure port 3, pass ultrapure water, and the ultrapure water flows into the premixing chamber 5 after passing through the adsorption flow channel 4 under the action of negative pressure. The nucleic acid adsorbed on the silica gel membrane is eluted into the premixing chamber 5 by the ultrapure water.

[0030] Based on the above principle, the microfluidic chip in this embodiment only needs a solution inlet, a waste liquid outlet 2, a negative pressure port 3, and an adsorption flow channel 4 and a premixing chamber 5 are provided in the chip 1 to complete the purification process of nucleic acid cleaning and elution. The microfluidic chip provided in this embodiment drives the liquid to flow in the corresponding flow channel and chamber in the chip by pumping negative pressure, abandoning the existing centrifugal drive and press drive methods, improving the controllability of liquid flow, and when using the solution provided by the present invention, the reaction liquid, eluent, and cleaning liquid are stored separately, and there is no need to preset them in the chip for storage, so there is no problem of liquid cross-flow. Therefore, the microfluidic chip provided by the present invention makes the flow of various liquids in the chip controllable, and it is not easy for various liquids to contaminate each other, ensuring the purity of the nucleic acid obtained after purification by the microfluidic chip.

[0031] In some embodiments, such as Figure 1 As shown, there are three solution inlets, namely the first solution inlet 6, the second solution inlet 7 and the third solution inlet 8. The second solution inlet 7 is arranged at the front end of the first solution inlet 6. The first solution inlet 6 and the second solution inlet 7 are connected in series and connected to the adsorption channel 4 through the second flow channel 9. The third solution inlet 8 is connected to the adsorption channel 4 through the third flow channel 10. The second flow channel 9 and the third flow channel 10 intersect and are connected to the end of the adsorption channel 4. An anti-overflow chamber 11 is arranged at the intersection of the second flow channel 9 and the third flow channel 10. The second flow channel 9 and the third flow channel 10 are respectively connected to the two ends of the top of the anti-overflow chamber 11.

[0032] like Figure 1As shown, the lysed bacterial sample, ethanol and ultrapure water enter the microfluidic chip in sequence. The lysed bacterial sample is first introduced into the first solution inlet 6, and then ethanol is introduced into the second solution inlet 7. The ethanol can clean the inner wall of the second flow channel 9; and the ultrapure water enters through a separate third flow channel 10, which ensures the purity of the ultrapure water and prevents the ultrapure water from being contaminated by the lysed bacterial sample and ethanol in the second flow channel 9. Such a design not only simplifies the structure, but also ensures the purity of the purified nucleic acid product; in addition, the overflow prevention chamber 11 provided at the intersection of the second flow channel 9 and the third flow channel 10 prevents the lysed bacterial sample, ethanol and ultrapure water from being mixed during the transfer process in the chip, so that various solutions will not contaminate each other, thereby ensuring the purity of the purified nucleic acid product.

[0033] like Figure 1 As shown, the solution provided in this embodiment reduces the contact between ultrapure water and the lysed bacterial sample and ethanol as much as possible, thereby improving the purity of ultrapure water and further improving the final purity of nucleic acid.

[0034] In other embodiments, three flow channels may be separately provided to correspond to the first solution inlet 6, the second solution inlet 7 and the third solution inlet 8 respectively. The connecting node between the third solution inlet 8 and the adsorption flow channel 4 needs to be located downstream of the other two connecting nodes to ensure the purity of the ultrapure water.

[0035] In some embodiments, such as Figure 1 As shown, the second flow channel 9 and the third flow channel 10 are both in the shape of a "U-shape" plus an "inverted U-shape" and are interconnected, and the tops of both ends of the top of the overflow prevention chamber 11 are connected to the "inverted U-shape" part.

[0036] The shapes and connection lines of the second flow channel 9 and the third flow channel 10 are as follows: Figure 1 As shown, with such a design, the first solution (the lysed bacterial sample) and the second solution (ethanol) flow vertically into the anti-overflow chamber 11. Under the action of negative pressure and gravity, the liquid vertically enters the anti-overflow chamber 11, thereby preventing the first solution (the lysed bacterial sample) and the second solution (ethanol) from overfilling the third flow channel 10 and contaminating the third flow channel 10, thereby preventing the third solution (ultrapure water) from being contaminated, thereby ensuring the purity of the nucleic acid and preventing the purified nucleic acid from containing a large amount of lysate and ethanol impurities. When analyzing the nucleic acid product, the impurities will interfere with the nucleic acid reaction, causing a false negative and obtaining an erroneous test result.

[0037] In some embodiments, such as Figure 1 As shown, in order to improve the purity of the purified product nucleic acid and prevent the first solution (the lysed bacterial sample) and the second solution (ethanol) from remaining at the intersection of the third flow channel 10 and the anti-overflow chamber 11 and contaminating the third flow channel 10, the connection between the anti-overflow chamber 11 and the third flow channel 10 is expanded.

[0038] In some embodiments, such as Figure 1 As shown, the chip is also provided with a vent 12 which can be closed or opened during operation, and the vent 12 is connected to the bottom of the premixing chamber 5; the vent 12 is connected to the bottom of the premixing chamber 5 through the first flow channel 13 and the fourth flow channel 14, the first flow channel 13 is connected to the fourth flow channel 14, the first flow channel 13 is connected to the bottom of the premixing chamber 5, the fourth flow channel 14 is connected to the vent 12, and the inner diameter of the fourth flow channel 14 is smaller than the inner diameter of the first flow channel 13.

[0039] The arrangement route of the air vent 12 is as follows: Figure 1 As shown, this design is for the convenience of control and simplification of the process. When the waste liquid outlet 2 is pumped with negative pressure to drive the first solution (the bacterial sample after lysis) and the second solution to pass through the membrane, if the inner diameter of the fourth flow channel 14 is equal to the inner diameter of the first flow channel 13, since the flow resistance of the air is smaller than the flow resistance of the liquid, when the waste liquid outlet 2 is pumped with negative pressure, the air at the air vent 12 will be drawn first, and the first solution (the bacterial sample after lysis) and the second solution will not be driven to pass through the silica gel membrane, resulting in the failure of the purification process. The inner diameter of the fourth flow channel 14 connected to the air vent 12 is designed to be smaller than the inner diameter of the first flow channel 13. , which increases the air resistance and ensures that when negative pressure is drawn at the waste liquid outlet 2, the first solution (the bacterial sample after lysis) and the second solution (ethanol) can be driven to pass through the silica gel membrane, so that the nucleic acid purification process proceeds smoothly, and the premixing chamber 5 can be connected to the atmosphere to prevent the premixing chamber 5 from being in a negative pressure state. This avoids the negative pressure in the premixing chamber 5 sucking the first solution (the bacterial sample after lysis) and the second solution (ethanol) into the premixing chamber 5 when negative pressure is drawn at the waste liquid outlet 2, thereby contaminating the purified product in the subsequent elution step, and avoiding the presence of lysis solution and cleaning solution impurities in the purified product, making the extracted product impure.

[0040] In some embodiments, such as Figure 1 As shown, in order to further balance the air pressure in the premixing chamber 5 and the outside, at least part of the first flow channel 13 is a reciprocating bending flow channel. Such a configuration extends the length of the outside atmosphere entering the premixing chamber 5 from the air vent 12, slows down the speed of the atmosphere entering the premixing chamber 5, and adjusts the atmospheric balance in the premixing chamber 5, which not only ensures that various solutions can smoothly enter the premixing chamber 5 and the nucleic acid purification process proceeds smoothly, but also avoids the film on the surface of the microfluidic chip from being sunken and the internal structure of the chip from being damaged, which may cause damage to the chip.

[0041] In some embodiments, such as Figure 1 As shown, the chip further includes a product outlet 17, which is connected to both the first flow channel 13 and the fourth flow channel 14. The product outlet 17 is used to collect the purified product, and in this embodiment, is used to collect the purified nucleic acid.

[0042] In some embodiments, such as Figure 1As shown, the negative pressure port 3 is connected to the top of the premixing chamber 5, and a liquid baffle 15 is fixedly arranged below the negative pressure port 3. In this way, when the negative pressure port 3 draws negative pressure on the premixing chamber 5, when the third solution elutes the purified product nucleic acid, the purified product nucleic acid is prevented from being drawn away by the negative pressure port 3, thereby avoiding the loss of the purified product nucleic acid.

[0043] In some embodiments, such as Figure 1 As shown, the chip includes a chip body 1 and a transparent covering film, the adsorption flow channel 4 and the premixing chamber 5 are arranged on the front of the chip body 1, the solution inlet, the waste liquid outlet 2 and the negative pressure port 3 are opened on the back, and the covering film is covered on the front of the chip body and can seal the adsorption flow channel 4 and the premixing chamber 5. The covering film can be covered on the front of the chip body 1 by various bonding methods such as film sealing and hot pressing.

[0044] In some embodiments, the biomacromolecule is a nucleic acid or a protein, and the biomacromolecule purified in this embodiment is a nucleic acid. Example

[0045] This example describes the method for using the microfluidic chip to purify nucleic acid provided in Example 1. Please refer to Figure 1 The method for using the microfluidic chip to purify nucleic acid provided in Example 1 is as follows:

[0046] Before using the microfluidic chip, all outlets and inlets on the chip body are in a closed state.

[0047] Step 1, open the air vent 12, connect the driving pump and the waste liquid outlet 2, introduce the lysed bacterial sample solution into the first solution inlet 6, start the driving pump to draw negative pressure at the waste liquid outlet 2, and the lysed bacterial sample solution flows out from the waste liquid outlet 2 after passing through the adsorption flow channel 4 under the action of negative pressure. The nucleic acid in the lysed bacterial sample solution is adsorbed by the silica gel membrane. After the lysed bacterial sample solution is drawn out, turn off the driving pump and close the first solution inlet 6;

[0048] Step 2, ethanol is introduced into the second solution inlet 7, and the driving pump is turned on to draw negative pressure at the waste liquid outlet 2. Under the action of negative pressure, ethanol flows out from the waste liquid outlet 2 after passing through the adsorption channel 4, and the silica gel membrane and the impurities thereon are cleaned by ethanol, and the nucleic acid is retained on the silica gel membrane; after the ethanol is discharged, the second solution inlet 7 is connected to the atmosphere, and negative pressure is continuously drawn to dry the ethanol residue on the silica gel membrane and the channel. After the silica gel membrane is dried, the driving pump is turned off, the waste liquid outlet 2 is closed, and the second solution inlet 7 is closed.

[0049] Step three, connect the driving pump and the negative pressure port 3, introduce ultrapure water into the third solution inlet 8, turn on the driving pump to draw negative pressure at the negative pressure port 3, and the ultrapure water flows into the premixing chamber 5 through the adsorption channel 4 under the action of negative pressure. The nucleic acid adsorbed on the silica gel membrane is eluted into the premixing chamber 5 by the ultrapure water. After purification is completed, turn off the driving pump, close the negative pressure port 3, and close the third solution inlet 8.

[0050] Step 4, transferring the purified nucleic acid from the chip to the outside for further analysis, connecting the drive pump and the product outlet 17, turning on the drive pump to draw negative pressure at the product outlet 17, and transferring the purified nucleic acid from the premixing chamber 5 to the outside under the action of negative pressure. Example

[0051] This embodiment provides another fluid control chip, such as Figure 2 As shown, on the basis of Example 1, a fourth solution inlet 16 is additionally provided at the premixing chamber 5, and the fourth solution inlet 16 is used to introduce the reaction solution. After step 3 in Example 2, the reaction solution is introduced into the fourth solution inlet 16, and the driving pump is turned on to draw negative pressure at the negative pressure port 3, and the reaction solution flows into the premixing chamber 5 under the action of the negative pressure;

[0052] This embodiment has all the advantages described in the first embodiment, which will not be described in detail here.

[0053] In addition, with such a design, in step 4 of Example 2, the mixed nucleic acid and reaction liquid can be transferred to the outside, and the tortuous first flow channel 13 can also play a role in mixing the nucleic acid and the reaction liquid in the process of transferring the nucleic acid and the reaction liquid to the outside. Therefore, the nucleic acid reaction liquid mixed solution obtained from the product outlet 17 can be directly used in the PCR detection experiment, that is, there is no need to add additional reaction liquid to the purified product nucleic acid, which replaces the cumbersome nucleic acid purification pre-treatment process in the traditional PCR experiment and simplifies the PCR experiment process. Example

[0054] The structure of the microfluidic chip provided in this embodiment is consistent with that of the first embodiment, and the method of use is consistent with that of the second embodiment, except that the microfluidic chip provided in this embodiment is used for purifying proteins.

[0055] To this end, the first solution used in this embodiment is preferably a cell sample after lysis, and the protein in the cell is released in the lysis solution; the second solution is preferably a low concentration imidazole solution, such as a 30mM imidazole solution; the filler in the adsorption channel 4 is preferably agarose resin; the third solution is a high concentration imidazole solution, such as a 400mM imidazole solution.

[0056] This embodiment has all the advantages described in the first embodiment, which will not be described in detail here.

[0057] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A fluid control chip, characterized in that: The invention comprises a chip, wherein the chip is provided with a solution inlet, a waste liquid outlet, and a negative pressure port, and an adsorption flow channel and a premixing chamber are provided in the chip; a filler capable of adsorbing biomacromolecules is preset in the adsorption flow channel; the solution inlet is connected to the adsorption flow channel, and the adsorption flow channel is connected to the waste liquid outlet and the premixing chamber; the negative pressure port is connected to the premixing chamber; a first solution, a second solution, and a third solution are sequentially introduced from the solution inlet; the waste liquid outlet is used to draw negative pressure and drive the first solution and the second solution to be discharged after passing through the adsorption flow channel; the negative pressure port is used to draw negative pressure and drive the third solution to flow into the premixing chamber, and the biomacromolecules are collected in the premixing chamber; wherein: The solution inlet is provided with three, namely, a first solution inlet, a second solution inlet and a third solution inlet, the second solution inlet is provided at the front end of the first solution inlet, the first solution inlet and the second solution inlet are connected in series and communicated with the adsorption channel through the second flow channel, the third solution inlet is communicated with the adsorption channel through the third flow channel, the second flow channel and the third flow channel intersect and communicate at the end of the adsorption channel, an overflow prevention chamber is provided at the intersection of the second flow channel and the third flow channel, and the second flow channel and the third flow channel are respectively communicated with the two ends of the top of the overflow prevention chamber; The second flow channel and the third flow channel are both in the shape of a "U-shape" plus an "inverted U-shape" and are interconnected, and the tops of both ends of the top of the overflow prevention chamber are connected to the "inverted U-shape" part; The place where the overflow prevention chamber is connected with the third flow channel is expanded.

2. The fluid control chip according to claim 1, characterized in that: The chip is also provided with an air vent which can be closed or opened during operation, and the air vent is connected to the bottom of the premixing chamber; the air vent is connected to the bottom of the premixing chamber through a first flow channel and a fourth flow channel, the first flow channel is connected to the fourth flow channel, the first flow channel is connected to the bottom of the premixing chamber, the fourth flow channel is connected to the air vent, and the inner diameter of the fourth flow channel is smaller than the inner diameter of the first flow channel.

3. The fluid control chip according to claim 2, characterized in that: At least a portion of the first flow channel is a reciprocating bending flow channel.

4. The fluid control chip according to claim 3, characterized in that: The chip further comprises a product outlet, and the product outlet is connected to both the first flow channel and the fourth flow channel.

5. The fluid control chip according to claim 1, characterized in that: The negative pressure port is communicated with the top of the premixing chamber, and a liquid baffle is fixedly arranged below the negative pressure port.

6. The fluid control chip according to claim 1, characterized in that: The chip includes a chip body and a transparent covering film, the adsorption flow channel and the premixing chamber are arranged on the front side of the chip body, the solution inlet, the waste liquid outlet and the negative pressure port are opened on the back side, and the covering film is covered on the front side of the chip body and can seal the adsorption flow channel and the premixing chamber.

7. The fluid control chip according to claim 1, characterized in that: The biomacromolecule is nucleic acid or protein.

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