Rapid extraction method for plasma DNA (deoxyribonucleic acid)

Abstract

The invention provides a plasma DNA rapid extraction method, and relates to the technical field of DNA separation and purification, and the plasma DNA rapid extraction method comprises the following steps: mixing plasma and a lysis solution, carrying out heating treatment, and injecting the plasma and the lysis solution into an extraction container at the same time; adding a magnetic bead suspension, and starting a motor to provide swing and oscillation effects; dNA is adsorbed to the surfaces of the magnetic beads in a high-salt environment to form a magnetic bead suspension; fixing the extraction container by using a magnetic frame, and controlling the magnetic beads to be concentrated; extracting supernate, and removing impurities; and adding a low-salt buffer solution to release DNA, controlling the magnetic beads to concentrate again, and extracting the released supernatant to obtain a purified DNA solution. When the motor controls the extraction container to rotate, a more uniform oscillation effect is provided, the mixing efficiency is improved, and when an internal solution is extracted, the internal solution can be far away from magnetic beads to the greatest extent, so that the purity of the finally extracted DNA solution is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gene detection, in particular to a method for rapid extraction of plasma DNA. BACKGROUND

[0002] In the field of gene detection services, DNA extraction is one of the important experimental steps. The magnetic bead method is a high-efficiency DNA extraction technology. The surface-modified magnetic microspheres are used to specifically adsorb DNA under high-salt conditions, and the impurities are quickly removed by magnetic separation. After washing, the DNA is eluted with a low-salt buffer. The whole process does not require centrifugation, and the operation is simple. It is suitable for micro-sample and high-throughput detection. Its advantages are fast speed and non-toxic reagents. It is widely used in biological industry, clinical diagnosis, molecular biology and sequencing field.

[0003] In the prior art, the magnetic bead method is used to separate and purify DNA. A magnetic stand device is needed, and a magnetic adsorption plate on the magnetic stand is used to realize the adsorption process of the internal magnetic beads, so as to achieve the purpose of gene detection. However, the conventional magnetic bead method for extracting DNA uses a simple magnetic stand structure. Since elution treatment is needed in the middle, the adsorbed DNA needs to be diffused again after completing this step and then be extracted. This causes the magnetic beads adsorbed by the conventional magnetic stand to be unable to be quickly concentrated in the bottom area, thereby causing a small amount of magnetic beads to be extracted when the DNA purification solution is extracted, resulting in contamination of the DNA solution. On the other hand, in the existing method for quickly extracting DNA by using magnetic beads, the magnetic beads need to be concentrated towards the test tube wall and diffused towards the middle for multiple times, which still requires a long time for manual shaking. The overall extraction process also needs to be improved. SUMMARY

[0004] In view of the deficiencies in the prior art, the present application aims to provide a method for rapid extraction of plasma DNA to solve the problems raised in the background art. The present application provides a more uniform shaking effect by controlling the rotation of the extraction container by a motor, improves the mixing efficiency, and maximizes the distance between the internal solution and the magnetic beads during extraction, thereby improving the purity of the extracted DNA solution. The concentration range of the magnetic beads is more flexible and accurate, and is suitable for large quantities of samples.

[0005] To achieve the above-mentioned purpose, the present application is realized by the following technical solution: a method for rapid extraction of plasma DNA, comprising the following steps: S1, mixing plasma and lysis solution, heating treatment, destroying cell membrane and releasing DNA, then injecting plasma and lysis solution into the inside of the extraction container, the extraction container is always supported by the magnetic stand at the bottom, and the plasma and lysis solution are injected by opening the residue discharge cover plate at the side of the extraction container; S2, add magnetic bead suspension, start motor, provide swing and shock effect, motor drives extraction container to rotate, swing and shock generated by rotation accelerate mixing process; S3, high salt environment makes DNA adsorbed to the surface of magnetic beads, forming magnetic bead suspension; S4, use magnetic frame to fix extraction container, start stage advancing mechanism, control magnetic beads to concentrate, and drive multiple magnetic rods to move slowly along the surface of extraction container from top to bottom through stage advancing mechanism; S5, use mixing assembly to extract supernatant, and sequentially add ethanol and washing buffer to remove impurities such as protein and lipid; S6, add low-salt buffer to release DNA, control magnetic beads to concentrate again, and extract supernatant after release to obtain purified DNA solution.

[0006] Further, in step S1, the pre-treatment process of the blood plasma is also included, the pre-treatment includes grinding treatment to the original blood plasma sample to break the tissues contained in the blood plasma, and the lysis solution includes proteinase K and chaotropic salt, and the heating treatment process in step S1 is at a temperature of 55℃ for 6 minutes.

[0007] Further, in step S2, after the magnetic bead suspension is added to the inside of the extraction container, the motor on the side is started, which directly drives the entire extraction container to reciprocate through the driving shaft, and the solution inside is uniformly shaken during the reciprocation, and the arc-shaped plate at the bottom of the extraction container is in contact with the rubber strip on the base, the bottom of the arc-shaped plate is provided with a protruding rod, and the shock effect is formed by the collision between the rod and the rubber strip.

[0008] Further, through the shaking and swinging process of the extraction container, it is ensured that the solution and magnetic beads inside the extraction container can be completely mixed, and after mixing, the extraction container is kept in a vertical state and fixed in the middle position by the motor control.

[0009] Further, in step S4, the stage advancing mechanism in the initial state is at the topmost position, and each magnetic rod is manually controlled to move to the top of the guide groove, the guide groove is integrally provided in an inclined state, and the outer side of the guide groove is higher than the end close to the upright column of the magnetic frame, so that each magnetic rod can roll towards the position of the upright column by relying on its own gravity.

[0010] Further, after each magnetic rod rolls to the end of the guide groove and abuts against the side of the lifting frame, the lifting frame is lifted to remove the blockage of the center shaft at both ends of the magnetic rod, so that the magnetic rod enters the inside of the strip-shaped hole, and the lifting frame is controlled to move downward again, and the connecting plate is integrally formed at the bottom of the lifting frame, the downward pressure is applied to the surface of the corresponding center shaft through the connecting plates on both sides, and the magnetic rod is driven to move downward.

[0011] Further, after the magnetic attraction rod moves downward, the surface of the magnetic attraction rod moves along the side edge of the extraction container, concentrates the magnetic beads in the extraction container that have adsorbed DNA during the movement, and synchronously guides the magnetic beads on the inner side downward with the downward movement of the magnetic attraction rod, until all the magnetic beads are concentrated in the bottom area of the extraction container.

[0012] Further, in step S5, the mixing assembly is inserted in the middle of the extraction container, and the mixing assembly is rotated by directly controlling the top pipe to drive the stirring plate at the bottom to rotate, and the stirring plate is first controlled to rotate to be parallel to the surface of the extraction container, and then the external needle tube is connected with the top of the control pipe.

[0013] Further, the external needle tube is pulled to completely extract the supernatant in the extraction container, and during the extraction process, the supernatant in the extraction container is rotated with the manual control of the control pipe around the plug-in shaft, drives the scraping strip at the end and the extraction hole at the bottom of the scraping strip to rotate, and in the rotating state, the extraction process of the supernatant is completed from the middle position of the extraction container.

[0014] Further, in step S6, the DNA on the magnetic beads is released again, and then the motor is controlled to rotate to drive the internal solution to mix, and at the same time, the scraping strip at the side of the stirring plate is contacted with the inner wall of the extraction container by rotating the control pipe, so that the magnetic beads adhered to the inner wall are uniformly mixed, and after the magnetic beads are adsorbed again, the internal solution is repeatedly pumped to discharge the DNA purification solution.

[0015] The beneficial effects of the present application are as follows: The method for rapidly extracting plasma DNA has the advantages of fast extraction speed, simple operation process, flexible and accurate control of the concentration range of magnetic beads, high and uniform mixing efficiency of the internal solution, and promotion of the development of the biological industry.

[0016] When the method for rapidly extracting plasma DNA controls the extraction container to rotate by the motor, the arc-shaped plate at the bottom of the extraction container directly contacts the rubber strip on the base to generate a high-frequency oscillation effect, which accelerates the diffusion efficiency between the internal magnetic beads and the solution, improves the mixing efficiency, and also accelerates the mutual gathering of different areas of the internal solution when the extraction container swings, so that the residual material can be discharged by the rotation angle when the solution is discharged subsequently.

[0017] The method for rapid extraction of plasma DNA can control the rotation switching of the mixing assembly in the extraction container, so that the bottom end of the stirring plate part is in vertical contact with the inner wall of the extraction container or is kept parallel and separated, by means of the switching process, the magnetic beads adhered to the inner wall of the extraction container can be scraped, and the magnetic beads can be farthest away from the magnetic beads when the supernatant is extracted, so that the purity of the finally extracted DNA solution is improved. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 A flowchart of the method for rapid extraction of plasma DNA; Figure 2 A schematic diagram of the installation of the magnetic frame and the extraction container used in the method for rapid extraction of plasma DNA; Figure 3 A schematic diagram of the structure of the magnetic frame part; Figure 4 A schematic diagram of the structure of the stage advancing mechanism part; Figure 5 A schematic diagram of the structure of the stage advancing mechanism part; Figure 2 An enlarged view of area A in the middle; Figure 6 A schematic diagram of the structure of the extraction container part; Figure 7 An enlarged view of the top of the extraction container; Figure 8 A schematic diagram of the structure of the mixing assembly part; In the figure: 1, extraction frame; 2, stage advancing mechanism; 3, extraction container; 4, mixing assembly; 5, bottom plate; 6, stand; 7, strip hole; 8, guide groove; 9, fixed plate; 10, inner gap; 11, base; 12, rubber strip; 13, end plate; 14, electric lifting rod; 15, lifting frame; 16, connecting plate; 17, outer gap; 18, center shaft; 19, magnetic attraction rod; 20, extrusion pad; 21, notch; 22, support frame; 23, plug-in shaft; 24, motor; 25, drive shaft; 26, control pipeline; 27, lever; 28, guide sleeve; 29, fitting plate; 30, clamping groove; 31, stirring plate; 32, scraping strip; 33, extraction hole; 34, plug-in slot; 35, arc plate; 36, slag discharge port. DETAILED DESCRIPTION

[0019] In order to make the technical means, creative features, purposes and effects realized by the present application easy to understand, the present application will be further described in conjunction with the specific embodiments.

[0020] Please refer to Figures 1 to 8The application provides the following technical scheme: a method for rapidly extracting plasma DNA, which has the advantages of rapid extraction speed, no need for centrifugal treatment in the whole process, simple and convenient operation process, more flexible and accurate control of the concentration range of magnetic beads, suitability for use in large batches of samples, higher and more uniform mixing efficiency of internal solutions, and promotion of the development of the biological industry. The embodiment provides a specific process of the above scheme, which comprises the following steps: S1, the plasma is mixed with a lysis solution, heated, the cell membrane is destroyed, and the DNA is released, then the plasma and the lysis solution are simultaneously injected into the inside of the extraction container 3, the extraction container 3 is always supported by the magnetic frame at the bottom, and the plasma and the lysis solution are injected by opening the residue discharge port 36 cover plate at the side of the extraction container 3.

[0021] The step also includes a pretreatment process of the plasma, the pretreatment includes grinding treatment on the original plasma sample, and tissues contained in the plasma are broken, the lysis solution comprises proteinase K and a chaotropic salt, and the heating treatment process in step S1 has a temperature of 55 DEG C and a heating time of 6 minutes; S2, the magnetic bead suspension is added, the motor 24 is started, swing and shock effects are provided, the motor 24 drives the extraction container 3 to rotate, and the mixing process is accelerated by means of the swing generated by rotation and the vibration at the bottom.

[0022] In the step, a magnetic frame and an extraction container 3 device are used, the two ends of the magnetic frame are welded with stand columns 6, strip-shaped holes 7 are formed in the surfaces of the stand columns 6, a fixed plate 9 is integrally formed on one side of the stand column 6, the surface of the fixed plate 9 is screwed with a motor 24, the output end of the motor 24 is inserted with a driving shaft 25, the tail end of the driving shaft 25 is fixedly connected with the surface of the extraction container 3, a bottom plate 5 is arranged at the bottom of the magnetic frame, the surface of the bottom plate 5 is integrally formed with a base 11, the top of the base 11 is attached with a rubber strip 12, an arc-shaped plate 35 is integrally formed at the bottom of the extraction container 3, the bottom of the arc-shaped plate 35 is provided with a protruding rod, and the protruding rod is used for contacting the rubber strip 12. In the application, the maximum sample capacity that can be injected into the inside of the extraction container 3 is 4 milliliters.

[0023] In the embodiment, after the magnetic bead suspension is added to the inside of the extraction container 3, the motor 24 at the side is started, the motor 24 directly drives the whole extraction container 3 to reciprocatingly swing, the solution in the inside is uniformly shaken in the process of swinging, meanwhile, the arc-shaped plate 35 at the bottom of the extraction container 3 is in contact with the rubber strip 12 on the base 11, the bottom of the arc-shaped plate 35 is provided with a protruding rod, and the shock effect is formed by the collision of the rod and the rubber strip 12. The solution and the magnetic beads in the inside of the extraction container 3 are completely mixed through the shock and swing processes of the extraction container 3, after mixing, the extraction container 3 is kept in a vertical state and fixed in the middle position by the motor 24.

[0024] When the extraction container 3 is controlled to rotate by the motor 24, the arc-shaped plate 35 at the bottom of the extraction container 3 directly contacts the rubber strip 12 on the base 11, thereby generating a high-frequency oscillation effect, which accelerates the diffusion efficiency between the internal magnetic beads and the solution, improves the mixing efficiency, and also accelerates the mutual gathering of different areas of the internal solution when the extraction container 3 swings, thereby achieving the purpose of discharging the residues through the rotation angle when the solution is subsequently discharged; S3, the DNA is adsorbed to the surface of the magnetic beads in a high-salt environment to form a magnetic bead suspension; S4, the extraction container 3 is fixed by the magnetic frame, the stage advancing mechanism 2 is started, the magnetic beads are controlled to concentrate, and the plurality of magnetic attraction rods 19 are driven by the stage advancing mechanism 2 to slowly move along the surface of the extraction container 3 from top to bottom.

[0025] In this step, the magnetic frame and the stage advancing mechanism 2 at both ends are used. The center shaft 18 is inserted and installed in the strip-shaped hole 7 at both ends of the magnetic frame. In the initial state, each magnetic attraction rod 19 is installed in the top guide groove 8. In the initial state, the end of the guide groove 8 is connected to the position of the strip-shaped hole 7. The center shaft 18 is blocked by the side of the lifting frame 15 at this position. The end plate 13 is integrally formed on the top of the lifting frame 15. The electric lifting rod 14 is screwed to the bottom of the end plate 13. The bottom of the electric lifting rod 14 is installed on the top of the stand 6. The magnetic attraction rod 19 is sleeved on the surface of the center shaft 18. The extrusion pad 20 is attached to both ends of the magnetic attraction rod 19. Each magnetic attraction rod 19 is supported in the middle of the two stands 6 by the extrusion pad 20.

[0026] In this embodiment, the stage advancing mechanism 2 is in the topmost position in the initial state, and each magnetic attraction rod 19 is manually controlled to move to the top end of the guide groove 8. The guide groove 8 is arranged in an inclined state as a whole. The end of the guide groove 8 outside is higher than the end close to the stand 6 on the magnetic frame, so that each magnetic attraction rod 19 can roll towards the position of the stand 6 by relying on its own gravity. After each magnetic attraction rod 19 rolls to the end of the guide groove 8, it is abutted to the side of the lifting frame 15. After the lifting frame 15 is lifted, the blockage of the center shaft 18 at both ends of the magnetic attraction rod 19 is removed, so that the magnetic attraction rod 19 enters the inside of the strip-shaped hole 7. The lifting frame 15 is controlled to move downward again. The connecting plate 16 is integrally formed on the bottom of the lifting frame 15. The downward pressure is applied to the surface of the corresponding center shaft 18 through the connecting plates 16 on both sides, so as to drive the magnetic attraction rod 19 to move downward. After the magnetic attraction rod 19 moves downward, the surface of the magnetic attraction rod 19 moves along the side of the extraction container 3. During the movement, the magnetic beads in the extraction container 3 which have adsorbed the DNA are concentrated, and the magnetic beads on the inside are guided and concentrated downward synchronously with the downward movement of the magnetic attraction rod 19, until all the magnetic beads are concentrated to the bottom layer area of the extraction container 3; S5, the supernatant is extracted by means of the mixing assembly 4, and ethanol and a washing buffer are sequentially added to remove impurities such as proteins and lipids.

[0027] In this step, the extraction container 3 and the mixing assembly 4 inside are used, the top of the extraction container 3 is arc-shaped, and a support frame 22 is installed on the top of the surface of the extraction container 3, an insertion shaft 23 is integrally formed on the top of the support frame 22, the support frame 22 is embedded into the insertion slot 34 on the surface of the guide sleeve 28 through the insertion shaft 23 on the top, a double-layered adhering plate 29 is attached to the bottom of the guide sleeve 28, and an arc-shaped notch 21 is formed on the top of the extraction container 3, the double-layered adhering plate 29 is used to adhere and block the inside and outside of the notch 21, an agitating plate 31 is integrally formed on the bottom of the guide sleeve 28, extraction holes 33 are formed on the top of the agitating plate 31, the inside of the agitating plate 31 is hollow, and a control pipeline 26 is connected to the top end of the agitating plate 31, and a lever 27 is integrally formed on both sides of the control pipeline 26.

[0028] In this embodiment, the mixing assembly 4 is inserted in the middle of the extraction container 3, the mixing assembly 4 is rotated by directly controlling the pipeline at the top end to drive the agitating plate 31 at the bottom to rotate, the agitating plate 31 is first controlled to rotate to be parallel to the surface of the extraction container 3, and then the top end of the control pipeline 26 is connected to the external needle tube. Pulling the external needle tube, the supernatant in the current extraction container 3 is completely extracted, and in the extraction process, the supernatant in the inside rotates around the insertion shaft 23 by manually controlling the control pipeline 26, drives the scraping strip 32 at the end and the extraction hole 33 at the bottom of the scraping strip 32 to rotate, and in the rotating state, the extraction of the supernatant is completed from the middle position of the extraction container 3.

[0029] When the internal solution is extracted, the mixing assembly 4 in the extraction container 3 can be controlled to rotate and switch, so that the agitating plate 31 at the bottom end is vertically contacted or kept parallel to the inner wall of the extraction container 3, by means of the switching process, the magnetic beads adhered to the inner wall of the extraction container 3 can be scraped, and the magnetic beads can be farthest away from the supernatant when the supernatant is extracted, so that the purity of the extracted DNA solution is improved. S6, the DNA is released by adding a low-salt buffer, the magnetic beads are controlled to concentrate again, and the supernatant after the release is extracted to obtain the purified DNA solution.

[0030] In this embodiment, the DNA on the magnetic beads is released again, and then the internal solution is mixed by controlling the motor 24 to rotate, and at the same time, the scraping strip 32 at the side of the agitating plate 31 is contacted with the inner wall of the extraction container 3 by rotating the control pipeline 26, so that the magnetic beads adhered to the inner wall are uniformly mixed, and after the magnetic beads are adsorbed again, the internal solution is repeatedly pumped to discharge the DNA purification solution.

[0031] After the extraction of the plasma sample is completed by the extraction container 3, if the subsequent extraction of the same batch of samples is performed, the internal residue is directly discharged and cleaned, if the subsequent cleaning of other batches of samples is needed, the entire extraction container 3 needs to be disassembled, sterilized and used, to ensure that the residual DNA can be eliminated.

[0032] The above shows and describes the basic principles and main features of the present application and the advantages of the present application, and it is obvious for those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application.

[0033] In addition, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that those skilled in the art can understand.

Claims

1. A method for rapid extraction of plasma DNA, characterized in that: The following steps are involved: S1. The plasma and lysate are mixed and heated to destroy the cell membrane and release DNA. The plasma and lysate are then injected simultaneously into the interior of the extraction container. The extraction container is always supported by a magnetic rack at the bottom. The plasma and lysate are injected by opening the slag discharge port cover on the side of the extraction container; S2. Add the magnetic bead suspension and start the motor to provide a swinging and oscillating effect. The motor drives the extraction container to rotate, and the swinging generated by the rotation and the vibration at the bottom accelerate the mixing process; S3, the high salt environment causes DNA to adsorb to the surface of the magnetic beads, forming a magnetic bead suspension; S4. Fix the extraction container with a magnetic rack, start the stage propulsion mechanism, control the magnetic beads to concentrate, and drive multiple magnetic rods to move slowly from top to bottom along the surface of the extraction container through the stage propulsion mechanism; S5. The supernatant is extracted with the help of a mixing assembly, and ethanol and washing buffer are added in sequence to remove impurities such as proteins and lipids; S6. Add low-salt buffer to release the DNA, control the magnetic beads to concentrate again, and extract the supernatant after release to obtain the purified DNA solution.

2. The method for rapid extraction of plasma DNA according to claim 1, characterized in that: Step S1 also includes a pretreatment process for plasma, which includes grinding the original plasma sample to break up the tissue contained in the plasma. The lysis solution includes proteinase K and chaotropic salt, and the heating treatment process temperature in step S1 is 55°C and the heating time is 6 minutes.

3. The method for rapid extraction of plasma DNA according to claim 1, characterized in that: In step S2, after adding the magnetic bead suspension into the interior of the extraction container, the motor on the side is started. The motor will directly drive the entire extraction container to swing back and forth through the drive shaft. During the swinging process, the solution inside will be evenly shaken. At the same time, the curved plate part at the bottom of the extraction container will contact the rubber strip on the base. A raised rod is provided at the bottom of the curved plate, and the collision between the rod and the rubber strip creates an oscillation effect.

4. The method for rapid extraction of plasma DNA according to claim 3, characterized in that: The oscillation and swinging process of the extraction container ensures that the solution and magnetic beads inside the extraction container are completely mixed. After mixing, the extraction container is controlled by a motor to maintain a vertical state and fixed in the middle position.

5. The method for rapid extraction of plasma DNA according to claim 3, characterized in that: In step S4, the stage propulsion mechanism in the initial state is at the top position, and each magnetic rod is manually controlled to move to the top to the guide groove. The guide groove is set to an inclined state as a whole, and the outer end of the guide groove is higher than the end close to the column on the magnetic frame, so that each magnetic rod can roll toward the position of the column by its own gravity.

6. The method for rapid extraction of plasma DNA according to claim 5, characterized in that: After each magnetic rod rolls to the end of the guide groove, it presses against the side of the lifting frame. After the lifting frame is lifted, the obstruction to the central axis at both ends of the magnetic rod is released, allowing the magnetic rod to enter the inside of the strip hole, and the lifting frame is controlled to move downward again. A connecting plate is integrally formed at the bottom of the lifting frame. The connecting plates on both sides simultaneously apply downward pressure to the corresponding central axis surface, driving the magnetic rod to move downward.

7. The method for rapid extraction of plasma DNA according to claim 6, characterized in that: After the magnetic rod moves downward, the surface of the magnetic rod moves along the side of the extraction container. During the movement, the magnetic beads inside the extraction container that have adsorbed DNA are concentrated. As the magnetic rod moves downward, the magnetic beads inside are synchronously guided downward and concentrated until all the magnetic beads are concentrated in the bottom area of ​​the extraction container.

8. The method for rapid extraction of plasma DNA according to claim 1, characterized in that: In step S5, a mixing component is inserted in the middle of the extraction container. The mixing component part drives the stirring plate at the bottom to rotate by directly controlling the rotation of the pipe at the top. The stirring plate is first controlled to rotate parallel to the surface of the extraction container, and then it can be docked with the top of the control pipe through an external needle.

9. The method for rapid extraction of plasma DNA according to claim 8, characterized in that: Pull the external needle to completely extract the supernatant liquid inside the current extraction container. During the extraction process, the internal supernatant liquid rotates around the plug-in shaft as the manually controlled pipe rotates, driving the scraper at the end and the extraction hole at the bottom of the scraper to rotate. In the rotating state, the supernatant liquid is extracted from the middle position of the extraction container.

10. The method for rapid extraction of plasma DNA according to claim 9, characterized in that: In step S6, the DNA on the magnetic beads is released again, and then the motor is controlled to rotate again to drive the internal solution to mix. At the same time, by rotating the control pipe, the scraper on the side of the stirring plate is brought into contact with the inner wall of the extraction container to ensure that the magnetic beads adhered to the inner wall are mixed synchronously and evenly. After the magnetic beads are adsorbed again, the internal solution suction process is repeated to complete the discharge of the DNA purification solution.

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