Microfluidic bags and fluid sample processing devices for nucleic acid extraction

Abstract

The present application discloses a microfluidic pouch and a fluid sample processing device for nucleic acid extraction. The microfluidic pouch includes a laminated membrane and a fixed binding area, a functional chamber, a valve area, a liquid inlet, a liquid outlet, etc. distributed in the laminated membrane. The size and shape of each functional chamber are defined by the boundary of the fixed binding area. The laminated membrane includes a first and a second laminated film, and the first and the second films are irreversibly combined in the fixed binding area, while in the functional chamber, the first and the second films can be switched between a state of separation and a state of adhesion under pressure; the valve area is used to connect adjacent functional chambers, in which an irreversible disposable valve structure is provided; each liquid inlet is connected to a corresponding functional chamber; and the liquid outlet is connected to a selected functional chamber. The microfluidic pouch of the present application has the advantages of functional integration, simple structure, easy use, and scalable production, and can be conveniently and efficiently used in scenarios such as nucleic acid extraction.

Description

Technical Field

[0001] The present invention particularly relates to a microfluidic bag for nucleic acid extraction and a fluid sample processing device, belonging to the field of microfluidic technology. Background Art

[0002] Nucleic acids are the carriers of genetic information, the most important biological information molecules, and the main objects of molecular biology research. Therefore, the extraction of nucleic acids is the most important and basic operation in molecular biology experimental techniques.

[0003] Traditional fully automated nucleic acid extraction technology is almost entirely based on a large XYZ three-dimensional platform, with a pipette mounted on the Z axis for precise, quantitative liquid transfer. This approach has the advantages of a mature mechanical design, high throughput, and relatively low and manageable costs, leading to its widespread adoption.

[0004] During the nucleic acid extraction process, samples need to go through several steps, including cell lysis, nucleic acid adsorption and purification, and nucleic acid elution and collection. For the vast majority of nucleic acid test samples, these steps are completed under liquid reaction environment conditions. In order to complete the multi-step reaction process, the carrier used to adsorb nucleic acids, such as magnetic beads, will undergo several transfers from one reactor to another, or the same reactor will be used continuously but the reagents need to be transferred out of the reactor after each step. If the aforementioned fully automatic nucleic acid extraction system is used for nucleic acid extraction, these transfers are all completed in an exposed environment. No matter how sophisticated the system design, when a large number of test samples are placed adjacent to each other in an open space and liquids are transferred by moving the XYZ three-dimensional platform, cross-contamination between samples, especially cross-contamination caused by the formation of aerosols by high-concentration samples, is almost impossible to completely eliminate. At the very least, it is difficult to prove the controllability of aerosol contamination, especially considering the uncontrollable factors of the instrument and equipment usage conditions and usage environment.

[0005] Another issue with the XYZ 3D platform is its highly limited flexibility. For most medical institutions, such as hospitals, daily testing volumes typically number in the dozens for each test item, and sample collection and testing times are uncertain. The technical characteristics of the XYZ 3D platform make its setup and use unsuitable for such low-throughput, high-batch operations.

[0006] The advent of microfluidic technology has made it possible to conduct continuous, highly integrated experimental procedures within tiny, confined spaces. These products are often referred to as Point-of-Care Tests (POCTs) due to their portability and ease of use. The most prominent examples include the Cepheid GeneXpert from the United States and the FilmArray from BioMérieux in France. However, the functional requirements of microfluidic products and their disposable nature often make their production costs incompatible with current market pricing. This has led to the emergence of testing products where microfluidic technology is becoming increasingly popular, but few have achieved large-scale application.

[0007] Since its inception, microfluidics technology has been characterized by the "sample to answer" goal, emphasizing process integrity and operational simplicity. However, this pursuit of process integrity overlooks a critical application reality: a large number of existing tests in the medical diagnostics industry are unable to transition from fully manual laboratory procedures to fully automated sample-to-answer processes due to system and management constraints, user habits, or limitations in reagent compliance. These existing tests require automated nucleic acid extraction products that are simple to operate and flexible enough to address the most time-consuming and labor-intensive "sample to nucleic acid" process in molecular testing. Furthermore, existing "Laboratory Developed Tests" (LDTs) worldwide are unable to leverage integrated microfluidic "sample to answer" automation technology to improve efficiency, remaining limited to the "sample to nucleic acid" phase. The need to expand traditional "sample to answer" microfluidics products to fully automated "sample to nucleic acid" processes with fewer steps and greater flexibility is clear and urgent.

[0008] On the other hand, for cell lysis, different types of cells require different cell destruction methods. Some processes only require mild treatment conditions, while others require drastic methods. For example, ultrasonic generators can be used to open most animal cell membranes, but are not suitable for some plant cells because the cell walls are very resistant to ultrasound. The lysis of animal cells can usually be achieved through chemical methods, but it is much more difficult for bacteria and fungi. These microorganisms often require strong cell wall breaking methods such as sonication through high-frequency sound, bead milling through glass microspheres, and mechanical disruption by blenders to achieve cell lysis. Although these cell lysis methods are widely used in laboratory operations, their application to microdevices is difficult, especially highly integrated devices for POCT (point-of-care testing) detection, such as microfluidic chips. In addition, in fields such as microchemical engineering, there is also a need to fully mix the reaction raw materials in microreaction systems, but there is no particularly effective method to achieve this goal. Summary of the Invention

[0009] The main purpose of this application is to provide a microfluidic bag, a fluid sample processing device and a nucleic acid extraction method to overcome the defects in the prior art.

[0010] To achieve the aforementioned invention objectives, the technical solutions adopted in this application include:

[0011] One aspect of the present application provides a microfluidic pouch for nucleic acid extraction, comprising a laminated membrane, at least one fixed binding region, a plurality of functional chambers, at least one valve region, and at least one liquid inlet, wherein the fixed binding region, the functional chamber, and the valve region are all distributed within the laminated membrane, and the size and shape of the functional chamber are defined by the boundaries of the fixed binding region, and each liquid inlet is connected to a corresponding functional chamber;

[0012] The laminated film comprises a first film and a second film that are stacked, and at least one of the first film and the second film is a flexible film;

[0013] The first film and the second film are irreversibly bonded in the fixed bonding area;

[0014] The first film and the second film in the functional chamber can switch between two states of separation and adhesion under pressure. When the first film and the second film in the functional chamber are separated from each other, the functional chamber can contain fluid.

[0015] An irreversible disposable valve structure is distributed in the valve area, and the disposable valve structure is connected between two adjacent functional chambers. When the disposable valve structure is changed from a closed state to an open state, fluid can flow between the two adjacent functional chambers;

[0016] The multiple functional chambers include a central chamber and multiple auxiliary chambers, and each auxiliary chamber is connected to the central chamber via a disposable valve structure;

[0017] Furthermore, when the first film and the second film are separated from each other in the central chamber, the distance between the first film and the second film is controllable, so that the central chamber has at least two states: limited opening and fully opening.

[0018] Another aspect of the present application further provides a fluid sample processing device, comprising:

[0019] The microfluidic bag,

[0020] More than one first squeezing mechanism, each first squeezing mechanism is provided corresponding to a functional chamber of the microfluidic bag and is used to selectively apply pressure to the corresponding functional chamber to drive the fluid to flow between the interconnected functional chambers.

[0021] Another aspect of the present application provides a use of the fluid sample processing device, such as use in extracting nucleic acids.

[0022] Compared with the prior art, this application has at least the following beneficial effects:

[0023] (1) The provided microfluidic pouch has the advantages of functional integration, simple structure, easy use, and scalable production, and can well meet the needs of POCT testing.

[0024] (2) When the microfluidic bag is in use, the entire experimental process is completely enclosed within the bag, eliminating the possibility of cross-contamination between multiple adjacent or non-adjacent liquid samples due to rapid vibration or movement of the sample gun during the experimental process (such as the nucleic acid extraction operation). The experimental process achieved through the flow of liquid in the closed system also eliminates the possibility of contamination caused by contaminants such as aerosols in the laboratory environment contacting the samples.

[0025] (3) When the provided microfluidic pouch is in use, as the liquid flows through the microfluidic channel between two adjacent functional chambers due to the pressure difference, the cavitation effect increases the energy within the liquid, thereby improving the efficiency of cell wall disruption. This efficiency improvement can be adjusted by adjusting the aspect ratio of the microfluidic channel, controlling the applied pressure, and adjusting the ratio of gas to liquid in the functional chamber storing the liquid.

[0026] (4) After the experimental process (e.g., nucleic acid extraction process) performed using the microfluidic pouch is completed, the obtained product (e.g., nucleic acid template extracted from a biological sample) is introduced into a sample tube that is sealed and connected to the microfluidic pouch and has a sealing gland via a sample outlet connected to a sealed microchannel. This sealed transfer ensures that the fully closed operation during the experimental process is further extended to the nucleic acid template transfer process. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The following describes exemplary embodiments of the present application with reference to the accompanying drawings. It should be understood that these specific descriptions are only used to teach those skilled in the art how to implement the present application, and are not intended to exhaust all possible methods of the present application, nor to limit the scope of protection of the present application.

[0028] Figure 1 This is a schematic structural diagram of a microfluidic pouch in one embodiment of the present application;

[0029] Figure 2 This is a schematic diagram of the layout of multiple functional chambers and valve areas in a microfluidic pouch in one embodiment of the present application;

[0030] Figure 3a-3j Schematic diagram of the structure of multiple first microfluidic channels in one embodiment of the present application;

[0031] Figure 4a-4g is a schematic diagram of various collision structures in one embodiment of the present application;

[0032] Figure 5 This is a schematic diagram of the connection between the liquid outlet and the eluent pool in one embodiment of the present application;

[0033] Figure 6 A schematic structural diagram of a fluid sample processing device in one embodiment of the present application. DETAILED DESCRIPTION

[0034] Some embodiments of the present application provide a microfluidic pouch for nucleic acid extraction, comprising a laminated membrane, at least one fixed binding region, a plurality of functional chambers, at least one valve region, and at least one liquid inlet. The fixed binding region, the functional chamber, and the valve region are all distributed within the laminated membrane, and the size and shape of the functional chamber are defined by the boundaries of the fixed binding region. One of the liquid inlets is connected to a corresponding functional chamber.

[0035] The laminated film comprises a first film and a second film that are stacked, and at least one of the first film and the second film is a flexible film;

[0036] The first film and the second film are irreversibly bonded in the fixed bonding area;

[0037] The first film and the second film in the functional chamber can switch between two states of separation and adhesion under the action of pressure. When the first film and the second film in the functional chamber are in the adhesion state, there is no physical space in the functional chamber that can accommodate fluid. When the first film and the second film in the functional chamber are in the separation state, in particular when the two films are separated and the flexible film therein is deformed, the functional chamber can accommodate fluid, that is, form a liquid storage chamber. The liquid storage chamber is mainly in the shape of a capsule, and therefore can also be called a liquid storage capsule or a microcapsule. The fluid includes liquid and / or gas.

[0038] An irreversible disposable valve structure is distributed in the valve area, and the disposable valve structure is connected between two adjacent functional chambers. When the disposable valve structure is changed from a closed state to an open state, fluid can flow between the two adjacent functional chambers;

[0039] The multiple functional chambers include a central chamber and multiple auxiliary chambers, and each auxiliary chamber is connected to the central chamber via a disposable valve structure;

[0040] Furthermore, when the first film and the second film are separated from each other in the central chamber, the distance between the first film and the second film is controllable, so that the central chamber has at least two states: limited opening and fully opening.

[0041] This application forms a microfluidic pouch by combining multiple thin films, with liquid storage chambers that appear and disappear as liquid enters and exits. This not only eliminates the "dead volume" problem that occurs when fluid is transferred between different areas of the microfluidic pouch, significantly improving fluid utilization, but also effectively avoids defects such as contamination caused by the incomplete transfer of fluid from a particular liquid storage chamber in existing microfluidic pouches, which results in a small amount of residual fluid. Furthermore, the microfluidic pouch of this application offers advantages such as easier preparation, lower cost, and shorter development cycles.

[0042] In one embodiment, when the central chamber is in a limited open state and the magnetic field strength in the central chamber is above a set value, magnetic particles contained in the fluid flowing through the central chamber can be efficiently captured in the central chamber by the magnetic field;

[0043] When the central chamber is in a fully open state and the magnetic field strength in the central chamber is less than the set value, the magnetic particles can freely flow into or out of the central chamber along with the fluid.

[0044] The set value can be adjusted accordingly according to the size of the central chamber, the material and specifications of the magnetic particles, etc.

[0045] The magnetic particles may be magnetic microbeads, microspheres, etc., such as superparamagnetic particles.

[0046] In one embodiment, when set pressures are alternately applied to the two auxiliary chambers containing fluid, the fluid can flow between the two auxiliary chambers through the central chamber.

[0047] In the present application, by setting up a central chamber with three states of fully open, partially open and fully closed, coordinating it with at least two auxiliary chambers, and combining it with regulating the intensity of the magnetic field applied in the central chamber, the capture of magnetic beads can be achieved conveniently and efficiently.

[0048] In one embodiment, when a set pressure is applied to the auxiliary chamber containing fluid, the disposable valve structure connected between the auxiliary chamber and the central chamber can be opened due to the fluid pressure, thereby allowing the fluid to flow into the central chamber.

[0049] The disposable valve structure can adopt a variety of weak connection structures known in the art, which are used to isolate the two functional chambers from each other and can be destroyed under certain heat, electromagnetic radiation or force to change from a closed state to an open state.

[0050] Preferably, the first and second films in the valve area are detachably combined to form the disposable valve structure, which can be destroyed by the impact of a fluid at a certain pressure, thereby changing from a closed state to an open state. For example, when a set pressure is applied to a functional chamber containing a fluid, the fluid can be impacted and destroyed by the irreversible disposable valve structure disposed between the functional chamber and another functional chamber, thereby allowing the fluid to enter the other functional chamber. The disposable valve structure can physically constitute a "valves" between different liquid storage chambers. These "valves" can be closed simply and quickly by selective squeezing, and the "valves" have no physical space after closing. Compared with traditional valves, they are easier to operate and do not cause fluid waste.

[0051] In one embodiment, a plurality of the auxiliary chambers are arranged around the central chamber in a direction coplanar with the laminated membrane. In this manner, fluid can flow directly from the auxiliary chambers into the central chamber without flowing across the chamber, thereby reducing the loss of the fluid or certain substances in the fluid and avoiding contamination of other chambers.

[0052] In one embodiment, the microfluidic pouch further comprises at least one first connection region, the first connection region being distributed within the laminated membrane, and the size and shape of the first connection region being also defined by the boundary of the fixed connection region; the first connection region being connected to two adjacent functional chambers, for example, between two adjacent auxiliary chambers, wherein the first film and the second film are detachably combined within the first connection region, wherein when the first film and the second film are separated from each other, a narrow first microfluidic channel is formed in the first connection region, and when a set pressure is applied to one of the functional chambers containing a fluid, the fluid can pass through the first microfluidic channel at a high speed (for example, a flow rate of 5-20 m / s) and enter the other functional chamber. The pressure difference between the two functional chambers and the high-speed outflow of the fluid can produce a cavitation-like effect, causing bubbles in the fluid to grow and rupture, thereby promoting more efficient lysis of substances such as thick-walled cell walls in the fluid or more rapid and thorough conduct of certain microchemical reactions. In the present application, a more ideal cavitation effect can be achieved by adjusting the pressure, the length and width of the first microfluidic channel, etc. to change the flow rate of the fluid after flowing through the first microfluidic channel.

[0053] More preferably, the first film and the second film in the first connection area can switch between two states of separation and mutual adhesion under the action of pressure. When the first film and the second film in the first connection area are separated from each other, the first microfluidic channel is formed in the first connection area, and when the first film and the second film in the first connection area are adhered to each other, the first microfluidic channel disappears, so that the first connection area no longer has a physical space that can accommodate liquid and gas.

[0054] In addition, after the first microfluidic channel is opened, the only connection between the two functional chambers is the first microfluidic channel, which can also be considered as an open valve. When the two functional chambers are squeezed alternately to make the fluid flow repeatedly between the two functional chambers, the fluid will generate a strong impact force when passing through the valve at high speed. This impact force can achieve the effect of vortex oscillation, so that the fluids contained in the two functional chambers are more fully mixed.

[0055] In one embodiment, the shape of the first microfluidic channel in the laminated membrane includes a polygonal or curved shape. The polygonal shape may be regular or irregular, such as a rectangle, triangle, rhombus, trapezoid, etc. The curved shape may be an arc, a sawtooth, a wavy line, etc., but is not limited thereto.

[0056] In one embodiment, a certain amount of solid particles can be added to the fluid, particularly solid particles composed of inert materials that do not react with the fluid, such as glass microspheres, hard resin microspheres, magnetic microspheres, ceramic particles, metal particles, etc. When these solid particles flow along with the fluid and pass through the first microfluidic channel, they can rapidly and repeatedly collide with certain substances in the fluid, such as cells or certain chemicals, thereby promoting the effective lysis of difficult-to-lyse cell structures or the thorough mixing of the chemicals.

[0057] In one embodiment, the microfluidic pouch further comprises a fluid blocking mechanism, which is distributed in the first microfluidic channel and leaves a gap with the inner wall of at least one side of the first microfluidic channel. By providing these fluid blocking structures, the flow direction, flow rate, etc. of the fluid in the first microfluidic channel can be regulated. In some cases, the fluid blocking mechanism can also collide with the high-speed fluid passing through the first microfluidic channel at high speed, and further promote the destruction and lysis of thick-walled cells in the fluid or faster and more frequent contact of chemical substances. Wherein, the fluid blocking mechanism can be formed by a partial area of ​​the fixed binding area extending into the first connection area.

[0058] In one embodiment, the microfluidic pouch further includes a collision structure disposed in front of the outlet of the first microfluidic channel and configured to collide with the fluid exiting the first microfluidic channel. By providing the collision structure, the fluid exiting the first microfluidic channel can collide with the collision structure at extremely high speeds. These intense collisions further promote the destruction and cleavage of certain difficult-to-break structures in the fluid or more rapid and frequent contact of chemical substances. The collision structure can be of regular or irregular shape and should be located a certain distance from the outlet of the first microfluidic channel.

[0059] In one embodiment, one of the auxiliary chambers is connected to another adjacent auxiliary chamber via a disposable valve structure and a first connecting area.

[0060] In one embodiment, the microfluidic pouch further comprises a liquid outlet and a second connection area, wherein the liquid outlet is connected to a functional chamber (e.g., an auxiliary chamber) via a second connection area, wherein the second connection area is also distributed within the laminated film, wherein the first film and the second film in the second connection area can switch between two states of separation and mutual adhesion under the action of pressure, wherein the first film and the second film in the second connection area can switch between two states of separation and mutual adhesion under the action of pressure, wherein when the first film and the second film in the second connection area are in a state of separation from each other, a second microfluidic channel for fluid to pass through is formed in the second connection area, and when the first film and the second film in the second connection area are in a state of adhesion, the physical space in the second connection area that can accommodate fluid and gas disappears. By providing a liquid outlet, the fluid processed by the microfluidic pouch can be discharged. The provision of the second connection area can form a valve between the functional chamber and the liquid outlet that is easy to open or close and leaves no physical space after closing, which is conducive to the output of the fluid with almost no residue and can also prevent contaminants in the external environment from entering the microfluidic pouch.

[0061] In one embodiment, the microfluidic pouch further comprises a third connection area, wherein a functional chamber (e.g., an auxiliary chamber) is sequentially connected to the liquid outlet via a disposable valve structure, a third connection area, and a second connection area. The third connection area is also distributed within the laminated membrane. Within the third connection area, the first film and the second film can switch between a state of separation and a state of mutual adhesion under pressure. When the first film and the second film within the third connection area are in a state of separation, a third microfluidic channel for fluid passage is formed within the third connection area. The diameter of the third microfluidic channel decreases along the direction of fluid flow. When the first film and the second film within the third connection area are in a state of mutual adhesion, the third microfluidic channel disappears. By providing the irreversible disposable valve structure and the third connection area, a structure similar to a one-way valve can be formed, which can better isolate the interior of the microfluidic pouch from the external environment.

[0062] In the present application, the pressure effect may be pressure provided by a force-applying mechanism (e.g., a squeezing mechanism) that cooperates with each functional chamber, the first connection area, the second connection area, and the third connection area. In some cases, the pressure effect may also include stress generated by deformation of the flexible film in the first film or the second film.

[0063] In one embodiment, the plurality of auxiliary chambers are respectively at least one sample pool, at least one lysis pool, at least one binding liquid pool, at least one washing liquid pool and at least one eluent pool, wherein one sample pool is connected to an adjacent lysis pool through one of the disposable valve structures and one of the first connecting areas, and one of the eluent pools is connected to the liquid outlet through one of the second connecting areas.

[0064] Furthermore, in the coplanar direction of the stacked membrane, the sample pool, lysis pool, binding liquid pool, washing liquid pool and eluent pool are distributed around the central chamber, and any one of the sample pool, lysis pool, binding liquid pool, washing liquid pool and eluent pool is independently directly connected to the central chamber through an irreversible disposable valve structure.

[0065] Furthermore, the sample pool, lysis pool, binding liquid pool, washing liquid pool, and eluent pool each have their own liquid inlet, and one of the eluent pools is also connected to a liquid outlet.

[0066] Furthermore, one of the eluent pools is connected to the liquid outlet in sequence through a disposable valve structure, a second connection area, and a third connection area.

[0067] In addition, one or more functional chambers may be provided to form a backup pool to meet some additional requirements.

[0068] In the present application, in the fixed bonding area, the first film and the second film are irreversibly bonded at least by thermocompression welding, ultrasonic welding or chemical bonding, but are not limited thereto.

[0069] In the present application, at least one positioning hole is further formed in the laminated membrane. The positioning hole allows workers to more quickly and accurately place the microfluidic pouch in the corresponding detection equipment, and more accurately perform operations such as selectively squeezing different functional chambers in the microfluidic pouch.

[0070] In the present application, the first film and the second film include any of PET film, PE film, PP film, PA film, PS film, and PI film, an aluminized film of any of these films, a composite film of any of these films and aluminum foil, a combination of multiple films, or a composite film of a combination of multiple films and aluminum foil, etc., but are not limited thereto. Preferably, both the first film and the second film are flexible films.

[0071] Some embodiments of the present application provide a fluid sample processing device comprising:

[0072] The microfluidic bag,

[0073] More than one first squeezing mechanism, each first squeezing mechanism is provided corresponding to a functional chamber of the microfluidic bag and is used to selectively apply pressure to the corresponding functional chamber to drive the fluid to flow between the interconnected functional chambers.

[0074] In one embodiment, the fluid sample processing device further includes one or more second squeezing mechanisms, each second squeezing mechanism being provided corresponding to a valve area of ​​the microfluidic bag and configured to selectively apply pressure to the corresponding valve area to open or close the corresponding valve.

[0075] In one embodiment, the first squeezing mechanism includes a magnetic squeezing mechanism, which is movable in at least the first, second, and third stations; wherein, at the first station, the magnetic squeezing mechanism squeezes the corresponding functional chamber and makes the first film and the second film fit tightly in the functional chamber; at the second station, the magnetic squeezing mechanism has no contact with the microfluidic bag, and the magnetic field strength applied by the magnetic squeezing mechanism to the corresponding functional chamber is below a set value; the third station is distributed between the first and second stations, and at the third station, the magnetic field strength applied by the magnetic squeezing mechanism to the corresponding functional chamber is greater than the set value. The value of the set value is determined by the magnetic strength and particle size of the magnetic beads. Generally speaking, when the magnetic field strength applied by the magnetic squeezing mechanism to the corresponding functional chamber is greater than the set value, it can exert sufficient magnetic attraction on the magnetic beads in the fluid and fix them. Conversely, if it is less than the set value, the magnetic beads in the fluid will not be adsorbed and fixed.

[0076] In one embodiment, the fluid sample processing device further includes a control unit, the control unit being connected to at least the first extrusion mechanism and configured to regulate the operating state of the first extrusion mechanism. Furthermore, the second extrusion mechanism may also be connected to the control unit, and its operating state may be regulated by the control unit. The control unit may be, but is not limited to, a PLC, an MCU, or a computer.

[0077] Furthermore, the fluid sample processing device may also include other auxiliary mechanisms, such as a drive mechanism, base, and cover plate of the aforementioned extrusion mechanism. These auxiliary mechanisms may be configured in accordance with methods well known in the mechanical field. The drive mechanism may be, but is not limited to, a pneumatic telescopic mechanism, an electromagnetic telescopic mechanism, a hydraulic telescopic mechanism, a linear motor, or other mechanical drive mechanisms.

[0078] Some embodiments of the present application provide a nucleic acid extraction method based on the fluid sample processing device, and the method includes:

[0079] S1, injecting sample, lysis solution, binding solution, first washing solution, second washing solution and eluent into the sample pool, lysis pool, binding solution pool, first washing solution pool, second washing solution pool and eluent pool of the microfluidic bag respectively, wherein magnetic beads are dispersed in the binding solution;

[0080] S2. Squeezing the sample pool or the lysis pool with a set squeezing force to allow the liquid sample to mix with the lysis solution through the first microfluidic channel. Then, alternately squeezing the sample pool and the lysis pool with the set squeezing force until the liquid sample and the lysis solution are fully mixed to obtain a lysed sample.

[0081] S3, closing the first microfluidic channel between the sample pool and the lysis pool, and squeezing the sample pool and / or the lysis pool and the binding liquid pool at a set squeezing force, so that the lysed sample and the binding liquid form a liquid path through the central chamber;

[0082] S4, moving the magnetic squeezing mechanism corresponding to the central chamber to the second station and alternately squeezing the sample pool, the lysis pool, and the binding liquid pool at a set squeezing force, so that the reaction liquid flows between the two functional chambers through the central chamber and the magnetic beads are fully suspended, so that the magnetic beads capture the nucleic acid in the sample;

[0083] S5. After the nucleic acid is captured, the magnetic squeezing mechanism corresponding to the central chamber reaches the third station and continues to alternately squeeze the sample pool, the lysis pool, and the binding liquid pool at a set squeezing force, so that the reaction liquid flows between two functional chambers through the central chamber, thereby capturing the magnetic beads with captured nucleic acid in the central chamber;

[0084] S6. After the magnetic beads are captured, the magnetic squeezing mechanism corresponding to the central chamber is moved to the first station to discharge the fluid in the central chamber;

[0085] S7, alternately squeezing the first washing liquid pool and the second washing liquid pool at a set squeezing force to form a liquid passage through the central chamber, and then referring to the operations of steps S4-S6 to complete the cleaning of the magnetic beads with captured nucleic acid;

[0086] S8. Squeeze the eluent pool with a set squeezing force to allow the eluent to enter the central chamber to elute the nucleic acid bound to the magnetic beads. Then, squeeze the central chamber with a set squeezing force to transfer the eluent into the eluent pool. Then, squeeze the eluent pool with a set squeezing force to allow the eluent to be output through the liquid outlet.

[0087] The set pressure mentioned in this application refers to a pressure exceeding a threshold value, and the threshold value varies with the specifications and materials of the microfluidic bag.

[0088] In addition, the fluid sample processing device of the present application can also be applied to the processing of other biological and chemical samples, such as PCR reactions, microchemical reactions, or other microbiochemical reactions.

[0089] The technical solution of the present application will be explained in more detail below in conjunction with several embodiments, but these specific descriptions are only used to teach those skilled in the art how to implement the present application, rather than to exhaustively enumerate all feasible methods of the present application, nor to limit the scope of the present application.

[0090] See also Figure 1-Figure 2 The present embodiment provides a microfluidic pouch for nucleic acid extraction, which is mainly composed of a laminated membrane 1000, a liquid inlet interface 2000, and a liquid outlet interface 3000. The laminated membrane 1000, the liquid inlet interface 2000, and the liquid outlet interface 3000 can be combined into a whole by hot pressing welding, ultrasonic welding, chemical bonding, etc.

[0091] The laminated film 1000, which may also be referred to as the pouch body, is primarily formed by laminating a first film 1001 and a second film 1002. At least one of the first film 1001 and the second film 1002 is preferably a flexible film having longitudinal stretchability. For example, the first film includes, but is not limited to, a composite film formed by a combination of one or more of PET film, PE film, PP film, PA film, PS film, and PI film, preferably a composite film. The second film includes, but is not limited to, a composite film formed by coextrusion or composite bonding of one or more of PET film, PE film, PP film, PA film, PS film, and PI film, such as an aluminized film or aluminum foil film, preferably a composite film.

[0092] In this embodiment, one or more fixed bonding areas and multiple functional chambers can be defined in the laminated film 1000 along the film plane. Furthermore, the fixed bonding areas divide the entire laminated film 1000 into a plurality of functional chambers along the film plane, i.e., the size and shape of the functional chambers are defined by the boundaries of the fixed bonding areas. Within the fixed bonding areas, the first and second films are irreversibly bonded by ultrasonic welding, bonding, hot pressing, or other methods, while within the functional chambers, the first and second films can switch between separation and adhesion under the action of external forces. Specifically, when a fluid under a certain pressure is injected into the functional chambers, the first and second films within the functional chambers deform and separate under the action of the fluid pressure, causing the functional chambers to assume a pouch-like structure capable of accommodating liquids and gases. When sufficient pressure is applied to the functional chambers by, for example, a squeezing mechanism, the first and second films within the functional chambers adhere to each other, and the physical space within the functional chambers for accommodating fluids and gases disappears.

[0093] In this embodiment, multiple functional chambers are primarily used as liquid storage chambers, including a sample reservoir 1101, a lysis reservoir 1103, a binding solution reservoir 1104, a first wash solution reservoir 1105, a second wash solution reservoir 1106, an eluent reservoir 1107, a central chamber 1108, a first backup reservoir 1109, and a second backup reservoir 1110. Each of these liquid storage chambers has a corresponding liquid inlet, such as a sample inlet 1301, a lysis solution inlet 1302, a binding solution inlet 1303, a first wash solution inlet 1304, a second wash solution inlet 1305, and an eluent inlet 1306. The sample inlet 1301 can be connected to a liquid inlet interface 2000.

[0094] Among them, the sample pool 1101, the lysis pool 1103, the binding liquid pool 1104, the first washing liquid pool 1105, the second washing liquid pool 1106, the eluent pool 1107, the first spare pool 1109, the second spare pool 1110, etc. are distributed in two dimensions as auxiliary chambers, surrounding the central chamber 1108 in the center. In scenarios where magnetic beads are needed to assist in capturing nucleic acids, the auxiliary chamber that requires the magnetic bead capture function (which can be named the magnetic bead capture chamber) is directly connected to the central chamber through a valve, avoiding the flow of magnetic beads across chambers, reducing the loss of magnetic beads, and avoiding contamination of reagents in other chambers. Furthermore, when it is necessary to perform a large volume solution magnetic bead cleaning and capture function, the reaction solution containing magnetic beads can be made to flow back and forth through the central chamber. This design structure ensures that the central chamber does not need to drive the liquid by compressing the volume, thereby minimizing the flow rate of the liquid in the central chamber and improving the magnetic bead capture efficiency.

[0095] Before liquid and gas are injected, the first and second films are tightly attached to each other within these functional chambers, leaving no physical space between them. Once the corresponding liquid and gas are injected into the corresponding functional chambers through the sample injection holes, the longitudinal stretchability of the flexible films generates internal pressure within the liquid, causing the first and second films to deform and separate, forming liquid storage chambers. Once the liquid within the liquid storage chambers is expelled due to pressure from the squeezing mechanism and the inherent stress of the flexible films, the first and second films reattach to each other within the corresponding functional chambers, eliminating the physical space between them.

[0096] In this embodiment, one or more valve regions can be defined within the laminated film 1000 along the film plane. Within each valve region, an irreversible, disposable valve structure is located. The disposable valve structure connects two adjacent functional chambers. When the disposable valve structure is closed, the two adjacent functional chambers are isolated from each other. When the disposable valve structure is open, fluid can flow between the two adjacent functional chambers. In this embodiment, within the valve region, a first film and a second film are releasably bonded to form the disposable valve structure. "Releasably bonded" herein means that this bond can be broken under certain conditions, such as a certain external force, thereby separating the first and second films within the valve region. Preferably, the first and second films within the valve region can be bonded by ultrasonic welding, adhesive bonding, hot press welding, or other methods, and this bond can be broken by fluid impact at a certain pressure. The disposable valve structure can have a regular or irregular shape, such as, but not limited to, a herringbone, V-shaped, zigzag, or wavy shapes. Generally, the width of the disposable valve structure is significantly smaller than the diameters of the two adjacent functional chambers. After two adjacent functional chambers are connected, the connection port is simply the torn valve. When the liquid storage bags formed by the two functional chambers are squeezed against each other, the squeezed liquid passes through the connection port at high speed, generating a strong impact force. This impact force can create a vortex oscillation effect, ensuring more thorough mixing of the liquids.

[0097] In this embodiment, there can be multiple valve areas, among which the multiple irreversible disposable valve structures can be named as sample valve 1201, sample lysis valve 1202, lysis valve 1203, combined liquid valve 1204, wash liquid valve 1205, wash liquid valve 2 1206, eluent valve 1207, liquid outlet valve 1208, etc.

[0098] In this embodiment, a first extrusion mechanism can be placed above or below each liquid storage chamber. When liquid flow is required, the corresponding first extrusion mechanism is pushed, causing the liquid in the corresponding functional chamber to be subjected to pressure. Each liquid storage area has its own corresponding valve area. The valve in each valve area (i.e., the aforementioned irreversible, disposable valve structure) will tear open when subjected to fluid pressure exceeding its rupture threshold, allowing the two liquid storage chambers connected by the valve to communicate with each other, allowing liquid to flow between the two liquid storage chambers.

[0099] In this embodiment, if it is necessary to extract nucleic acids with the aid of auxiliary media such as magnetic beads, the first extrusion mechanism can adopt a structural member with a magnetic bead capture function, such as a magnet with a flat surface, and the magnetic extrusion mechanism can move relatively at the first station, the second station and the third station at different distances from the magnetic bead capture chamber; wherein, at the first station, the magnetic extrusion mechanism squeezes the magnetic bead capture chamber with its flat surface, so that the first film and the second film fit tightly in the functional chamber and the dead volume in the magnetic bead capture chamber is minimized; at the second station, the magnetic extrusion mechanism is away from the magnetic bead capture chamber, and at this time, the magnetic force generated by the magnet embedded in the magnetic extruder on the magnetic bead capture chamber is extremely weak and cannot capture the magnetic beads in the liquid flowing through the magnetic bead capture chamber; the third station is located between the first station and the second station, and at the third station, the magnetic extrusion mechanism is in close contact with one of the two films forming the magnetic bead capture chamber but is separated from the other film, that is, the magnetic bead capture chamber forms a thin liquid flow columnar structure. When the liquid containing magnetic beads passes through this thin liquid flow column structure, all the magnetic beads will be affected by the magnet on the magnetic squeezing mechanism and may be adsorbed in the magnetic bead capture chamber.

[0100] Taking the central chamber 1108 as an example, a movable magnet can be set at its corresponding position to capture magnetic beads. When the magnet is fully extended, it fits in the central chamber area, draining the liquid in the central chamber. The magnet moves back a small distance, and the central chamber becomes a thin liquid flow columnar structure, which can capture the magnetic beads in the liquid flowing through the central chamber. When the magnet is completely retracted, the central chamber can no longer feel the magnetic force, and the magnetic beads can flow through the central chamber along with the liquid. The position of the magnet from the central chamber is divided into the first station, the second station, and the third station. The first station will allow the magnet to pop out completely, directly fit tightly against the pouch and completely press the central chamber, fitting the upper and lower layers of film in the central chamber together. This function can discharge the liquid in the central chamber out of the central chamber; the second station will completely retract the magnet, moving it away from the central chamber. At this time, the magnetic beads captured in the liquid in the central chamber can be released, and the magnetic beads can flow with the liquid; the third station is between complete pop-out and complete retraction, which will keep a certain distance between the upper and lower layers of film in the central chamber. This position is mainly used for magnetic bead capture.

[0101] Furthermore, a corresponding second squeezing mechanism can be provided above or below each valve zone to serve as a physical valve. If the valve within each valve zone is damaged by liquid pressure, the corresponding physical valve can be used to provide a barrier function. Specifically, the second squeezing mechanism can squeeze the corresponding valve zone to form a seal, thereby blocking the flow of liquid.

[0102] In this embodiment, at least one first connection area can also be defined in the laminated film 1000 along the membrane plane direction. A first connection area is connected between two adjacent functional chambers. Preferably, the width of the first connection area is much smaller than the diameter of the two functional chambers. In the first connection area, the first film and the second film are detachably combined so that the first connection area can form a first microfluidic channel. When a set extrusion force is applied to one of the functional chambers containing fluid, so that the fluid passes through the first microfluidic channel into the other functional chamber, due to the effect of pressure and the geometric size limitation of the microfluidic channel, the fluid passes through the narrow first microfluidic channel at high speed. The pressure difference between the two functional chambers and the high-speed outflow of the fluid produce a cavitation-like effect, causing the bubbles in the fluid to grow and burst.

[0103] In this embodiment, an irreversible disposable valve structure and a first connection area can be provided between the functional chamber forming the sample reservoir 1101 and the functional chamber forming the lysis reservoir 1103. This first connection area is used to form a first microfluidic channel 1102. When a compressive force is applied to the sample reservoir 1101, the liquid within it escapes through the first microfluidic channel 1102. Due to the narrow structure of the first microfluidic channel 1102, the liquid flow rate within the channel increases rapidly. This causes the liquid pressure within the channel to drop. When the local absolute pressure of the high-speed flowing liquid drops below the saturated vapor pressure in the current environment, the air dissolved in the water is released, forming numerous tiny cavitation bubbles. After these cavitation bubbles flow into the lysis reservoir 1103 with the liquid, they burst in an implosion-like manner due to changes in external factors such as the release of pressure. During the cavitation bursting process, the bubbles generate a transient local high temperature and high pressure, forming shock waves and microjets. This process can even enable chemical reactions that are impossible at normal temperature and pressure. These burst vacuoles will promote the destruction of difficult-to-lyse structures (such as bacteria, fungi, cells containing cell wall structures, etc.) and optimize the lysis effect.

[0104] The first microfluidic channel 1102 can have a variety of regular or irregular shapes, such as a triangle, trapezoid, drum, wave, or interdigitated shape. The shape of the first microfluidic channel 1102 can be changed to improve the efficiency of cavitation formation. Furthermore, the length and width of the first microfluidic channel 1102 can be adjusted to further increase the flow rate of the liquid passing through the channel, thereby achieving a desired lysis effect. For example, in this embodiment, the width of the first microfluidic channel 1102 can be set to 0.1-10 mm, and the length can be set to 0.1 mm-50 mm.

[0105] In addition, a fluid blocking mechanism can be set in the first microfluidic channel. In the coplanar direction of the stacked membrane, the fluid blocking mechanism can be a variety of regular or irregular shapes, such as rectangle, triangle, diamond, lattice, etc. It can be connected to the inner wall of one side of the first microfluidic channel and leave a gap between it and the inner wall of the other side of the first microfluidic channel, or it can leave a gap between it and the inner walls on both sides of the first microfluidic channel, so as to regulate the fluidic parameters of the fluid in the first microfluidic channel, and can also collide with the high-speed fluid passing through the first microfluidic channel at high speed.

[0106] In this embodiment, a typical shape and structure of the first microfluidic channel 110201 can be referred to Figure 3a A high-pressure area 110202 and a low-pressure area 110203 are formed on both sides thereof, and when the fluid enters the low-pressure area 110203 from the high-pressure area 110202 through the first microfluidic channel 110201, cavitation bubbles 110204 are formed.

[0107] Exemplarily, the first microfluidic channel can also be Figure 3b The first microfluidic channel 11020101 shown, Figure 3c The first microfluidic channel 11020102 shown, Figure 3d The first microfluidic channel 11020103 shown, Figure 3e The first microfluidic channel 11020104 shown, Figure 3f The first microfluidic channel 11020105 shown, Figure 3g The first microfluidic channel 11020106 shown, Figure 3h The first microfluidic channel 11020107 shown, Figure 3i The first microfluidic channel 11020108 shown or Figure 3j Any of the first microfluidic channels 11020109 shown. The fluid blocking mechanism therein may be Figure 3d Rectangular fluid blocking mechanism 11020501, Figure 3f The interdigital fluid blocking mechanism 11020502, Figure 3g The diamond-shaped fluid blocking mechanism 11020503, Figure 3j The lattice type fluid blocking mechanism 11020504, etc.

[0108] In this embodiment, a collision structure can also be provided in front of the outlet of the first microfluidic channel. In the coplanar direction of the laminated membranes, the collision structure can have various regular or irregular shapes, such as triangles, rectangles, arcs, broken lines, and circles, and is used to violently collide with the high-speed fluid output from the first microfluidic channel. A certain distance should be provided between the collision structure and the outlet of the first microfluidic channel to ensure smooth flow of fluid from one functional chamber to another.

[0109] In this embodiment, a typical collision structure 110207 can be found in Figure 4a When the liquid flows out of the first microfluidic channel 1102, it hits the inner wall of the lysis pool 1103 or the collision structure 110207 at a very high speed. These violent collisions further promote the destruction and cleavage of the difficult-to-cleave structure. Figure 4b The collision structure shown is 11020701, Figure 4c The collision structure shown is 11020702, Figure 4d The collision structure shown is 11020703, Figure 4e The collision structure shown is 11020704, Figure 4f The collision structure shown is 11020705 or Figure 4g Any of the collision structures 11020706 shown.

[0110] In this embodiment, a certain number of glass microspheres 110206 and the like can be optionally added to the lysate. When the glass microspheres flow along with the liquid, when passing through any of the first microfluidic channels 11020101 to the first microfluidic channels 11020108, the sample cells collide with the glass microspheres rapidly and repeatedly, which more efficiently promotes the effective lysis of difficult-to-lyse structures.

[0111] See Figure 1 and Figure 5In this embodiment, a liquid outlet 1307 is also formed in the laminated membrane 1000, and the liquid outlet 1307 is connected to the liquid outlet interface 3000. The functional chamber for forming the eluent pool 1107 can be connected to the liquid outlet 1307 via a second connection area 1111. The second connection area is also distributed in the laminated membrane. In the second connection area, the first film and the second film are detachably combined. When the first film and the second film in the second connection area are separated, a second microfluidic channel 13072 is formed in the second connection area for fluid to pass through. The second microfluidic channel 13072 is preferably curved, such as S-shaped. Specifically, when no liquid is passing through, the first film and the second film in the second connection area are tightly attached, leaving no physical space. When the corresponding chamber is squeezed to generate internal pressure for the liquid therein, the pressure exerted by the fluid entering the second connection area causes the first film and the second film to separate, forming a second microfluidic channel 13072 with a physical space, allowing liquid to be transferred within the second microfluidic channel 13072.

[0112] Preferably, a valve area can be provided between the functional chamber for forming the eluent pool 1107 and the liquid outlet 1307. The irreversible, disposable valve structure therein can be designated as the liquid outlet valve 1208. Furthermore, a third connection area can be provided between the functional chamber for forming the eluent pool 1107 and the liquid outlet 1307. The third connection area is also distributed within the laminated membrane. Within the third connection area, the first and second films are detachably coupled. When the first and second films within the third connection area are separated, a third microfluidic channel 13071 is formed within the third connection area, through which fluid can pass. The third microfluidic channel can have a variable diameter structure, specifically, its diameter decreasing along the direction of liquid flow.

[0113] The functional chamber for forming the eluent pool 1107 can be connected to the liquid outlet 1307 through the liquid outlet valve 1208 , the third microfluidic channel 13071 and the second microfluidic channel 13072 in sequence.

[0114] Also, please refer again to Figure 1-Figure 2 A number of positioning holes, such as a first positioning hole 1401 and a second positioning hole 1402, may be formed on the laminated film, especially on its edge, to guide the positioning of the microfluidic bag and occupy less effective space on the microfluidic bag.

[0115] A method for extracting nucleic acids using the microfluidic bag of this embodiment may include the following steps:

[0116] S1. Add the sample to be extracted into the sample pool 1101 through the injection port 2000 to complete the sample addition action;

[0117] S2. Place the microfluidic bag into a corresponding extraction device.

[0118] S3. Close all physical valves.

[0119] S4. Open the physical valve above sample lysis valve 1202, applying pressure to sample reservoir 1101 and breaking sample lysis valve 1202. The liquid in the sample reservoir flows through sample lysis valve 1202 into lysis reservoir 1103, mixing the sample and lysis solution. Sample reservoir 1101 is squeezed, released, lysis reservoir 1103 is squeezed, and released, allowing the liquid to flow back and forth between the sample reservoir and lysis reservoir, achieving thorough mixing of the sample and lysis solution.

[0120] S5. Close the physical valve at sample lysis valve 1202 to cut off the flow of liquid between the sample and lysis reservoirs. Open the physical valves at sample valve 1201, lysis valve 1203, and binding solution valve 1204. This disrupts sample valve 1201, lysis valve 1203, and binding solution valve 1204, allowing the sample, lysis solution, and binding solution to mix, allowing the magnetic beads to capture nucleic acids from the sample.

[0121] S6. Raise the magnet below the central chamber 1108 to the third station. The magnet is pressed against the bottom surface of the microfluidic pouch, but maintains a distance from the top surface. Liquids in the sample reservoir, lysis reservoir, and binding solution reservoir flow sequentially through the central chamber, capturing the magnetic beads within the central chamber.

[0122] S7. Raise the magnet lift position below the central chamber 1108 to the first position to discharge the waste liquid remaining in the central chamber.

[0123] S8. After the magnetic beads are captured, the waste liquid is discharged into the sample pool 1101 and the lysis pool 1103. The corresponding physical valves below the sample valve 1201 and the lysis valve 1203 are closed. The magnet below the central chamber 1108 is lowered to the second position to release the magnetic beads.

[0124] S9. Use the liquid in the first washing liquid pool 1105 twice to rinse the magnetic beads in the central chamber 1108.

[0125] S10, the waste liquid after washing is discharged into the combined liquid pool 1104 and the first washing liquid pool 1105.

[0126] S11, washing the magnetic beads in the central chamber with the liquid in the second washing liquid tank 1106. After completion, the waste liquid is discharged into the second washing liquid tank 1106.

[0127] S12. Use the liquid in the eluent pool 1107 to elute the nucleic acid in the central chamber 1108 and transfer the eluent to the eluent pool 1107.

[0128] S13: Open the physical valve above the liquid outlet valve 1208 and close the physical valve above the eluent valve 1207. Squeeze the eluent pool 1107 so that the liquid is discharged into the PCR tube below through the liquid outlet, completing the nucleic acid extraction process.

[0129] The aforementioned extraction device can also be considered as a fluid sample processing device, which can have various structures. Figure 6 As shown, a fluid sample processing device may include a bag gland 4001, a nucleic acid extraction bag 4002, an actuator 4003, a physical valve 4004, a sealing ring 4005, a magnetic actuator 4006, a bag support block 4007, an air inlet 4008, etc. The nucleic acid extraction bag 4002 adopts the aforementioned microfluidic bag, the actuator 4003 and the magnetic actuator 4006 serve as the aforementioned first extrusion mechanism, and the physical valve 4004 serves as the aforementioned second extrusion mechanism. The actuator 4003, the magnetic actuator 4006, the physical valve 4004, etc. can be driven by pneumatic, electric, etc. In this embodiment, the gas drive method is mainly adopted, and the gas pressure range is 0.1-0.6MPa. For example, the magnetic actuator 4006 can be driven by a magnet motion cylinder 4009.

[0130] In this embodiment, at least one set of actuators 4003 is placed corresponding to each functional chamber of the microfluidic pouch to promote the flow of liquid in the corresponding chamber;

[0131] A set of physical valves 4004 is provided corresponding to each valve area of ​​the microfluidic pouch. When the valves are damaged, the physical valves serve to block the liquid.

[0132] A sealing ring 4005 can be placed at the rear end of the actuator 4003 and valve 4004, forming a seal with the groove in the bag support block 4007. When gas enters the groove in the bag support block 4007 through the air inlet 4008, it pushes the actuator or valve forward. When the actuator 4003 moves forward and encounters the bag 4002, it pushes the corresponding chamber forward. However, due to the obstruction of the bag gland 4001, the actuator 4003 eventually abuts against the gland 4001, expelling the liquid from the corresponding chamber in the bag 4002 and achieving a single liquid extrusion. When the air pressure at the air inlet is released, the actuator no longer exerts a squeezing force and no longer squeezes the corresponding chamber in the bag. When the valve 4004 moves forward, it separates the flow of liquid between the two chambers. Optionally, devices such as a rebound spring and a stop screw can be added to the rear of the actuator and valve to limit the actuator's extension distance and provide active rebound functions.

[0133] In this embodiment, the air intake volume of the air inlet can be controlled by using PWM (pulse width modulation) and other methods. By adjusting the PWM high-level time, the air intake time within a single control cycle can be controlled to achieve the purpose of controlling the single air intake volume. In this way, the actuator 4003 and the magnet motion cylinder 4009 can be slowly supplied with air. In this way, the actuator or cylinder can be slowly extended and retracted. At the same time, the extension distance of the actuator and the cylinder can be controlled by controlling the air intake volume. For example, the magnet motion cylinder 4009 has a first air inlet and a second air inlet. If positive pressure is applied to the first air inlet continuously, the cylinder will extend, and if positive pressure is applied to the second air inlet continuously, the cylinder will retract. When a fixed number of PWM waves are applied to the first air inlet, the cylinder will not be fully extended. By adjusting the number of PWM waves, the working position of the magnet actuator 4006 can be switched.

[0134] Although the present application has been described with reference to illustrative embodiments, it will be understood by those skilled in the art that various other changes, omissions, and / or additions may be made without departing from the spirit and scope of the present application, and that substantial equivalents may be substituted for the elements of the described embodiments. In addition, many modifications may be made to adapt specific circumstances or materials to the teachings of the present application without departing from the scope of the present application. Therefore, it is not intended herein to limit the present application to the disclosed specific embodiments for carrying out the present application, but rather it is intended that the present application will include all embodiments within the scope of the appended claims. Furthermore, unless specifically stated, any use of the terms first, second, etc. does not indicate any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another.

Claims

1. A microfluidic bag for nucleic acid extraction, characterized in that The device comprises a laminated membrane, at least one fixed bonding area, a plurality of functional chambers, at least one first connection area, at least one valve area, at least one liquid inlet, and a collision structure, wherein the fixed bonding area, the functional chamber, the first connection area, and the valve area are all distributed within the laminated membrane, and the size and shape of the functional chamber and the first connection area are defined by the boundaries of the fixed bonding area, and each liquid inlet is connected to a corresponding functional chamber; The laminated film comprises a first film and a second film that are stacked, and at least one of the first film and the second film is a flexible film; The first film and the second film are irreversibly bonded in the fixed bonding area; The first film and the second film in the functional chamber can switch between two states of separation and adhesion under pressure. When the first film and the second film in the functional chamber are separated from each other, the functional chamber can contain fluid. The first film and the second film are detachably combined in the first connection area, wherein when the first film and the second film are separated from each other, a narrow first microfluidic channel is formed in the first connection area, and when a set pressure is applied to one of the functional chambers containing fluid, the fluid can pass through the first microfluidic channel at a high speed and enter the other functional chamber, and the collision structure is disposed in front of the outlet of the first microfluidic channel and is used to collide with the fluid output from the first microfluidic channel; An irreversible disposable valve structure is distributed in the valve area, and the disposable valve structure is connected between two adjacent functional chambers. When the disposable valve structure is changed from a closed state to an open state, fluid can flow between the two adjacent functional chambers; The multiple functional chambers are respectively a central chamber and a plurality of auxiliary chambers. In a direction coplanar with the laminated membrane, the multiple auxiliary chambers are arranged around the central chamber, and each auxiliary chamber is directly connected to the central chamber via one of the disposable valve structures. One of the auxiliary chambers is connected to another adjacent auxiliary chamber via one of the disposable valve structures and one of the first connecting areas. Furthermore, when the first film and the second film are separated from each other in the central chamber, the distance between the first film and the second film is controllable, so that the central chamber has at least two states: limited opening and fully opening.

2. The microfluidic pouch according to claim 1, wherein: When the central chamber is in a limited open state and the magnetic field strength in the central chamber is above a set value, magnetic particles contained in the fluid flowing through the central chamber can be captured in the central chamber by the magnetic field; When the central chamber is in a fully open state and the magnetic field strength in the central chamber is less than the set value, the magnetic particles can freely flow into or out of the central chamber along with the fluid.

3. The microfluidic pouch according to claim 1, wherein: When a set pressure is applied to the auxiliary chamber containing fluid, the disposable valve structure connected between the auxiliary chamber and the central chamber can be opened due to the fluid pressure, thereby allowing the fluid to flow into the central chamber.

4. The microfluidic pouch according to claim 3, wherein: When set pressures are alternately applied to the two auxiliary chambers containing fluid, the fluid can flow between the two auxiliary chambers through the central chamber.

5. The microfluidic pouch according to claim 1, wherein: The first film and the second film are detachably combined in the valve area to form the disposable valve structure.

6. The microfluidic pouch according to claim 1, wherein: The high speed refers to a flow rate of 5-20 m / s.

7. The microfluidic pouch according to claim 1, wherein: In the first connection area, the first film and the second film can switch between two states of separation and mutual adhesion under the action of pressure. When the first film and the second film in the first connection area are separated from each other, the first microfluidic channel is formed in the first connection area, and when the first film and the second film in the first connection area are adhered to each other, the first microfluidic channel disappears. The fluid includes liquid and gas.

8. The microfluidic pouch according to claim 1, wherein: The first microfluidic channel has a width of 0.1-10 mm and a length of 0.1 mm-50 mm.

9. The microfluidic pouch according to claim 1, wherein: The shape of the first microfluidic channel in the laminated membrane includes a polygonal shape or a curved shape.

10. The microfluidic pouch according to claim 1, wherein: The microfluidic pouch further includes a fluid blocking mechanism, which is distributed in the first microfluidic channel and has a gap between the fluid blocking mechanism and at least one inner wall of the first microfluidic channel.

11. The microfluidic pouch according to claim 1, wherein: The microfluidic pouch also includes a liquid outlet and a second connection area, the liquid outlet is connected to one of the auxiliary chambers through a second connection area, and the second connection area is also distributed in the laminated membrane. In the second connection area, the first film and the second film can switch between two states of separation and mutual adhesion under the action of pressure. When the first film and the second film in the second connection area are separated from each other, a second microfluidic channel for fluid to pass through is formed in the second connection area, and when the first film and the second film in the second connection area are adhered to each other, the second microfluidic channel disappears.

12. The microfluidic pouch according to claim 11, wherein: The microfluidic pouch also includes a third connection area, and one of the auxiliary chambers is connected to the liquid outlet in sequence through a disposable valve structure, a third connection area and a second connection area. The third connection area is also distributed in the laminated membrane. In the third connection area, the first film and the second film can switch between two states of mutual separation and mutual adhesion under the action of pressure. When the first film and the second film in the third connection area are in a state of mutual separation, a third microfluidic channel for fluid to pass through is formed in the third connection area. The diameter of the third microfluidic channel decreases along the direction of fluid flow, and when the first film and the second film in the third connection area are in mutual adhesion, the third microfluidic channel disappears.

13. The microfluidic pouch according to claim 11, wherein: The multiple auxiliary chambers are respectively at least one sample pool, at least one lysis pool, at least one binding liquid pool, at least one washing liquid pool and at least one eluent pool, wherein one sample pool is connected to an adjacent lysis pool through a disposable valve structure and a first connecting area, and one eluent pool is connected to the liquid outlet through a second connecting area.

14. The microfluidic pouch according to claim 1, wherein: The first film and the second film include any one of PET film, PE film, PP film, PA film, PS film, and PI film, an aluminized film of any one of the films, a composite film of any one of the films and aluminum foil, a combination of multiple films, or a composite film of a combination of multiple films and aluminum foil.

15. The microfluidic pouch according to claim 1, wherein: In the fixed bonding area, the first film and the second film are irreversibly bonded at least by thermocompression welding, ultrasonic welding or chemical bonding.

16. The microfluidic pouch according to claim 1, wherein: At least one positioning hole is also formed on the laminated film.

17. A fluid sample processing device, characterized in that: include: The microfluidic pouch according to any one of claims 1 to 16, More than one first squeezing mechanism, each first squeezing mechanism is provided corresponding to a functional chamber of the microfluidic bag and is used to selectively apply pressure to the corresponding functional chamber to drive the fluid to flow between the interconnected functional chambers.

18. The fluid sample processing device according to claim 17, wherein: Also includes: More than one second squeezing mechanism, each second squeezing mechanism is provided corresponding to a valve area of ​​the microfluidic bag and is used to selectively apply pressure to the corresponding valve area to open or close the corresponding valve.

19. The fluid sample processing device according to claim 17 or 18, characterized in that: The first squeezing mechanism includes a magnetic squeezing mechanism, which can move at least in the first station, the second station and the third station; wherein, at the first station, the magnetic squeezing mechanism squeezes the corresponding functional chamber and makes the first film and the second film fit tightly in the functional chamber; at the second station, the magnetic squeezing mechanism has no contact with the microfluidic bag, and the magnetic field strength applied by the magnetic squeezing mechanism to the corresponding functional chamber is below a set value; the third station is distributed between the first station and the second station, and at the third station, the magnetic field strength applied by the magnetic squeezing mechanism to the corresponding functional chamber is greater than the set value.

20. The fluid sample processing device according to claim 17 or 18, characterized in that: The fluid sample processing device further includes a control unit, which is connected to at least the first squeezing mechanism and is used to regulate the working state of the first squeezing mechanism.

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