Magnetic rod for purifying DNA by magnetic bead method

Abstract

The utility model discloses a magnetic force stick for magnetic bead method purifies DNA, including combination stick and non -magnetic outer tube, combination stick includes non -magnetic component and magnetic component, and non -magnetic component is fixedly connected with magnetic component, forms combination stick, and the non -magnetic component top of magnetic component is provided with the cylinder small hole, is provided with connecting spring in the cylinder small hole, and connecting spring both ends respectively fixed one telescopic ball, non -magnetic outer tube includes the pipe body, and the inside of pipe body is provided with the pipe cavity, and one pair of crossbeam is provided with symmetry at the pipe cavity top, and the vertical beam of crossbeam vertical setting is connected, and the pipe cavity bottom is provided with the conical pipe bottom, and the combination stick is provided in non -magnetic outer tube, and the pipe bottom of pipe cavity is closely contacted with the bottom of magnetic component of combination stick, and combination is through telescopic ball and is stuck on the pipe cavity wall, to reach the fixed purpose of combination stick and non -magnetic outer tube.

Description

Technical Field

[0001] This utility model relates to the field of DNA extraction technology, specifically a magnetic rod for purifying DNA using the magnetic bead method. Background Technology

[0002] Deoxyribonucleic acid (DNA) extraction and purification are crucial steps in molecular biology experiments. Common DNA extraction and purification methods include the Chelex-100 method, magnetic bead method, silica bead method, organic solvent method, and column chromatography. Among these, the magnetic bead method has become the primary method in many laboratories due to its high DNA purity and the ability to be purified using automated extraction instruments.

[0003] The principle of DNA purification using magnetic beads is as follows: Cells are lysed using cell lysis buffer, releasing DNA molecules. Under certain conditions (such as high salt and appropriate pH), the DNA molecules are adsorbed onto specially modified magnetic beads (e.g., coated with silica). Then, under the influence of a magnetic field, the DNA-adsorbed magnetic beads are separated from the liquid, and the magnetic beads are recovered. Afterward, the magnetic beads are washed 1-2 times with washing buffer (i.e., rinsing solution) to remove impurities. After each wash, the magnetic beads are adsorbed again under a magnetic field, and the supernatant is discarded. After rinsing, the DNA is eluted from the magnetic beads with pure water or TE buffer under certain conditions to obtain a DNA solution. However, due to the high cost of automated extraction instruments, many small laboratories do not possess them. Therefore, many technicians use the traditional method of manually extracting DNA using magnetic beads with a magnetic rack. This method has problems such as being time-consuming and labor-intensive, inefficient in processing batches of samples (usually more than 8), prone to errors, and difficult to completely remove residual liquid when aspirating the rinsing solution (residual liquid may affect subsequent experiments). Utility Model Content

[0004] The purpose of this invention is to provide a magnetic rod for purifying DNA using the magnetic bead method, so as to solve the problems of ease of use, cost-saving and rapid purification mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: A magnetic rod for purifying DNA using magnetic beads includes a combination rod and a non-magnetic outer tube, with the combination rod disposed inside the non-magnetic outer tube; the combination rod includes a non-magnetic component, with a magnetic component disposed at the bottom of the non-magnetic component; the non-magnetic outer tube includes a tube body, with an open-topped cavity disposed inside the tube body, and a pair of crossbeams symmetrically disposed along the outer edge of the top of the cavity.

[0006] As a further improvement of the magnetic rod for DNA purification by magnetic beads according to this utility model: the bottom of the non-magnetic component is provided with a groove, and the top of the magnetic component is provided with a protrusion relative to the groove; the non-magnetic component and the magnetic component are fixedly connected by the groove and the protrusion.

[0007] As a further improvement of the magnetic rod for DNA purification by magnetic bead method of this utility model: the bottom of the non-magnetic component is provided with a groove, and the groove is provided with an internal thread; relative to the groove, the top of the magnetic component is provided with a protrusion, and the protrusion is provided with an external thread; the protrusion and the groove are threadedly connected to each other.

[0008] As a further improvement of the magnetic rod for DNA purification by magnetic bead method according to this utility model: the combined rod and the non-magnetic outer tube are fitted with a gap.

[0009] As a further improvement of the magnetic rod for DNA purification by magnetic bead method of this utility model: a cylindrical hole is provided on the non-magnetic component, and the cylindrical hole extends horizontally through the non-magnetic component; a connecting spring is provided inside the cylindrical hole, and a telescopic ball is fixed at each end of the connecting spring.

[0010] As a further improvement to the magnetic rod for DNA purification by magnetic bead method of this utility model: the crossbeam is vertically connected to the vertical beam.

[0011] As a further improvement to the magnetic rod for purifying DNA using the magnetic bead method of this utility model: the bottom of the tube is conical.

[0012] As a further improvement of the magnetic rod for purifying DNA using the magnetic bead method according to this utility model: the magnetic component is conical in shape relative to the conical tube bottom.

[0013] Compared with the prior art, the beneficial effects of this utility model are: This invention efficiently removes residual rinsing liquid, enabling rapid, manual, batch extraction and purification of high-quality DNA from cell lysates. It offers advantages such as ease of use, cost-effectiveness, and rapid purification. Compared to existing products, this product features a non-magnetic outer tube with a conical bottom, accommodating both flat-bottomed and other irregularly shaped rods. Furthermore, the conical structure significantly increases the area of ​​the magnetic adsorption region compared to some existing flat-bottomed designs. The vertical beam structure along the non-magnetic outer tube adds stress points, making it more convenient to use. Attached Figure Description

[0014] Figure 1 This is a three-dimensional structural schematic diagram (cross-sectional view) of the present invention.

[0015] In the diagram: 1. Combination rod; 11. Non-magnetic component; 12. Protrusion; 13. Magnetic component; 14. Groove; 15. Cylindrical hole; 16. Telescopic ball; 17. Connecting spring; 2. Non-magnetic outer tube; 21. Crossbeam; 22. Vertical beam; 23. Tube body; 24. Tube cavity; 25. Tube bottom. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0017] refer to Figure 1 This utility model provides a technical solution: a magnetic rod for purifying DNA using magnetic beads. The magnetic rod includes a combination rod 1 and a non-magnetic outer tube 2. In use, the combination rod 1 is inserted into the non-magnetic outer tube 2, and there is a gap fit between the combination rod 1 and the non-magnetic outer tube 2 to facilitate the placement of the combination rod 1 into the non-magnetic outer tube 2. The specific settings are as follows: The composite rod 1 includes a non-magnetic component 11 and a magnetic component 13. The non-magnetic component 11 has a cylindrical structure, and a groove 14 is carved out on the bottom end face of the non-magnetic component 11. The groove 14 is a cylindrical cavity. Corresponding to the groove 14, a protrusion 12 of the same shape (cylindrical structure) is provided on the top of the magnetic component 13. The non-magnetic component 11 and the magnetic component 13 can be rigidly connected through the groove 14 and the protrusion 12 (for example, the groove 14 and the protrusion 12 are set as an interference fit). This detachable structure facilitates product replacement and maintenance. Alternatively, an internal thread can be provided on the inner side wall of the groove 14, and an external thread can be provided on the outer side wall of the protrusion 12. The non-magnetic component 11 and the magnetic component 13 can be threadedly connected through the connection of the internal and external threads.

[0018] like Figure 1 As shown, at least one cylindrical hole 15 is drilled in the side wall of the non-magnetic component 11. The cylindrical hole 15 penetrates the non-magnetic component 11 laterally. A connecting spring 17 is provided inside the cylindrical hole 15. A telescopic ball 16 is fixed at each end of the connecting spring 17. It is necessary to ensure that when the connecting spring 17 is fully released, the outer edge of the telescopic ball 16 pushes out of the cylindrical hole 15.

[0019] The non-magnetic outer tube 2 includes a tube body 23, and the tube body 23 has an open-topped cavity 24 inside. A suitable gap is left between the non-magnetic component 11 and the inner wall of the cavity 24 (that is, to ensure a clearance fit between the combined rod 1 and the non-magnetic outer tube 2). The gap is filled by two telescopic balls 16 at both ends of the connecting spring 17 (when the connecting spring 17 is fully released, the outer walls of the two telescopic balls 16 need to be exposed outside the outer wall of the non-magnetic component 11). The non-magnetic component 11 is locked in the tube body 23 by the elastic deformation of the connecting spring 17.

[0020] A pair of crossbeams 21 are symmetrically arranged on the outer edge of the top opening of the cavity 24 (i.e., the outer edge of the tube body 23), and a vertical beam 22 is vertically arranged at the outer end of the crossbeams 21 (this is arranged here for easy gripping). The bottom of the cavity 24 is a conical tube bottom 25; relative to the conical tube bottom 25, the bottom of the magnetic component 13 is set with a corresponding conical structure.

[0021] The bottom of the magnetic component 13 is in close contact with the tube bottom 25, and the non-magnetic component 11 is secured to the inner wall of the tube cavity 24 by the telescopic ball 16, so as to achieve the purpose of fixing the combined rod 1 and the non-magnetic outer tube 2.

[0022] Working principle: This invention is used for the rinsing and elution steps in DNA purification using magnetic beads. In practical use, it can be used for purification of single samples or batch purification.

[0023] I. Single sample purification steps: 1. Take five 1.5ml conical tubes and place them on the test tube rack in sequence, labeling them A, B, C, D and E respectively.

[0024] 2. Place an appropriate amount of lysis buffer in conical tube A (the cells have been lysed and DNA molecules have been released), an appropriate amount of wash buffer 1 in conical tube B, an appropriate amount of wash buffer 2 in conical tube C, no liquid in conical tube D (it is an empty tube), and an appropriate amount of elution buffer in conical tube E.

[0025] 3. Place an appropriate amount of adsorption solution into the conical tube A containing the lysis buffer, add an appropriate amount of magnetic beads, vortex to mix, and let stand at room temperature for 10 minutes, shaking 2-3 times during the standing period to ensure that the magnetic beads are in a suspended state. Then open the cap of the conical tube A and place the magnetic rod into the conical tube A. When placing it, a pair of crossbeams 21 are locked at the upper end of the opening of the conical tube A, and the bottom 25 of the non-magnetic outer tube 2 is immersed below the liquid surface, so that the magnetic components 13 of the combined rod are all below the liquid surface. At this time, the magnetic beads bound with DNA are adsorbed to the bottom of the outer side of the bottom 25 of the non-magnetic outer tube 2 (i.e., the position of the magnetic components 13).

[0026] 4. Remove the magnetic rod with the magnetic beads adsorbed and place it into conical tube B, using the same method as in step 3. Then, press down on the pair of crossbeams 21 with one hand and hold the upper end of the non-magnetic component 11 with the other hand, pulling upwards. At this time, the telescopic ball 16 retracts and slides upwards along the wall of the tube cavity 24. When the bottom of the magnetic component 13 is above the liquid surface, release the upper end of the non-magnetic component 11, and the telescopic ball 16 pops out onto the wall of the tube cavity 24, fixing the combined rod 1 to the inner wall of the tube cavity 24 through the telescopic ball 16. At this point, the magnetic beads leave the magnetic field environment and begin to move in the liquid. The magnetic beads diffuse in the liquid. Hold the vertical beam 22 with your hand and rotate it along the opening of the cone-shaped tube B to promote rapid dispersion of the magnetic beads in the liquid. Then, hold the pair of horizontal beams 21 with one hand and grasp the upper end of the non-magnetic component 11 with the other hand and push it downward. At this time, the telescopic ball 16 retracts and slides down the wall of the lumen 24 until the bottom of the magnetic component 13 is in close contact with the bottom of the tube 25 (at this time, stop pushing). Then, the magnetic beads with DNA adsorbed to the bottom of the non-magnetic outer tube 2 (i.e., the corresponding position of the magnetic component 13), completing the first rinse.

[0027] 5. Take out the magnetic rod with the magnetic beads adsorbed and put it into the C-shaped conical tube. The operation method is the same as step 4 to complete the second rinsing.

[0028] 6. Take out the magnetic rod with the magnetic beads adsorbed and put it into the D-shaped conical tube. When placing it, the pair of crossbeams 21 are placed at the upper end of the opening of the D-shaped conical tube, and the lower end of the non-magnetic outer tube 2 is placed inside the cavity of the D-shaped conical tube, without contacting any cavity wall or bottom, and is in a suspended state. Let it dry for 1-2 minutes.

[0029] 7. Remove the magnetic rod with the adsorbed magnetic beads from the conical tube D and place it into the conical tube E, following the same placement method as in step 3. Then, hold the pair of crossbeams 21 with one hand and grasp the upper end of the non-magnetic component 11 with the other hand, and pull upwards. At this time, the telescopic ball 16 retracts and slides upwards along the inner wall of the tube 24 until the bottom of the magnetic component 13 is above the liquid surface. Then, release the upper end of the non-magnetic component 11, and the telescopic ball 16 pops out onto the wall of the tube 24, fixing the combined rod 1 to the inner wall of the tube 24 through the telescopic ball 16. At this time, the magnetic beads leave the magnetic field environment, separate from the non-magnetic outer tube 2, and begin to diffuse in the liquid. Hold the vertical beam 22 by hand and rotate it along the opening of the conical tube to promote rapid dispersion of the magnetic beads in the liquid. At this time, take out the magnetic rod and place it in the conical tube D. When placing it, a pair of horizontal beams 21 are stuck at the upper end of the opening of the conical tube D. The lower end of the non-magnetic outer tube 2 is placed inside the cavity of the conical tube D and does not contact any cavity wall or bottom, and is in a suspended state. Then, put the conical tube E containing liquid and magnetic beads into a shaking metal bath, heat and shake at 800-1200 rpm and 65°C for 10 minutes. The DNA is separated from the magnetic beads and enters the elution solution. Take out the conical tube E from the shaking metal bath and put it into the test tube rack.

[0030] 8. Remove the magnetic rod from conical tube D and place it into conical tube E, following the same placement method as in step 3. Press down on the pair of crossbeams 21 with one hand and hold the upper end of the non-magnetic component 11 with the other hand, pushing it downwards. At this time, the telescopic ball 16 retracts and slides down along the inner wall of the tube 24 until it comes into close contact with the bottom of the magnetic component 13 and the tube bottom 25 (stop pushing at this point). The magnetic bead then adheres to the bottom end of the non-magnetic outer tube 2 (i.e., the corresponding position of the magnetic component 13). Then remove the magnetic rod and place it into conical tube D. At this point, the separation of the magnetic bead and the solution containing DNA molecules is complete. The liquid in conical tube E is the solution containing DNA. The entire DNA purification process is now complete.

[0031] According to the single sample purification protocol, DNA can be purified manually in batches by configuring multiple sets of conical tubes and magnetic rods under the same conditions. It is simple to use, quick to extract DNA, does not require automated machinery, and saves costs.

[0032] Finally, it should be noted that the above content is only used to illustrate the technical solution of this utility model, and is not intended to limit the scope of protection of this utility model. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of this utility model do not depart from the essence and scope of the technical solution of this utility model.

Claims

1. A magnetic rod for purifying DNA using magnetic beads, comprising a combination rod (1) and a non-magnetic outer tube (2), wherein the combination rod (1) is disposed within the non-magnetic outer tube (2); characterized in that: The combined rod (1) includes a non-magnetic component (11), and a magnetic component (13) is provided at the bottom of the non-magnetic component (11). The non-magnetic outer tube (2) includes a tube body (23), and the tube body (23) has an open-topped cavity (24) inside. A pair of crossbeams (21) are symmetrically arranged on the outer edge of the top of the tube body (23).

2. A magnetic rod for purifying DNA using magnetic beads according to claim 1, characterized in that: The bottom of the non-magnetic component (11) is provided with a groove (14), and a protrusion (12) is provided on the top of the magnetic component (13) relative to the groove (14). The non-magnetic component (11) and the magnetic component (13) are fixedly connected by a groove (14) and a protrusion (12).

3. A magnetic rod for purifying DNA using magnetic beads according to claim 1, characterized in that: The bottom of the non-magnetic component (11) is provided with a groove (14), and an internal thread is provided in the groove (14). Relative to the groove (14), a protrusion (12) is provided on the top of the magnetic component (13), and an external thread is provided on the protrusion (12). The protrusion (12) and the groove (14) are threaded together.

4. A magnetic rod for purifying DNA using magnetic beads according to claim 1, characterized in that: The combined rod (1) and the non-magnetic outer tube (2) are fitted with a clearance.

5. A magnetic rod for purifying DNA using magnetic beads according to claim 4, characterized in that: The non-magnetic component (11) is provided with a cylindrical hole (15), which extends laterally through the non-magnetic component (11). A connecting spring (17) is provided inside the small hole (15) of the cylinder, and a telescopic ball (16) is fixed at each end of the connecting spring (17).

6. A magnetic rod for purifying DNA using magnetic beads according to claim 1, characterized in that: The crossbeam (21) is vertically connected to the vertical beam (22).

7. A magnetic rod for purifying DNA using magnetic beads according to claim 1, characterized in that: The bottom of the cavity (24) is a conical tube bottom (25).

8. A magnetic rod for purifying DNA using magnetic beads according to claim 5, characterized in that: The magnetic component (13) is conical in shape relative to the conical tube bottom (25).

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