Extraction tool for exfoliated cell DNA direct expansion

Abstract

The utility model relates to the technical field of forensic physical evidence detection, and discloses an extraction tool for direct expansion of DNA (deoxyribonucleic acid) of cast-off cells. The extraction tool for exfoliated cell DNA direct expansion comprises a storage tube, an extraction handle is in contact with the interior of the storage tube, a hollow tube is arranged at the bottom of the extraction handle, a plurality of silica gel microspheres are placed in the hollow tube and can pop out of the bottom of the hollow tube, a sliding groove is formed in the extraction handle, and the silica gel microspheres can pop out of the bottom of the hollow tube. The interior of the sliding groove is in threaded connection with a threaded round block, and the interior of the threaded round block is slidably connected with a rotating block. When the DNA extraction device is used, the silica gel microspheres are arranged, so that a DNA extraction step is omitted, the loss of a detection material during extraction is avoided, DNA detection is carried out by adopting an extraction-free direct amplification technology, the detection success rate is higher, time and labor are saved, meanwhile, the push rod is arranged, DNA extraction equipment can be repeatedly used, the cost is reduced, the efficiency is improved, and the economic cost is saved.

Description

Technical Field

[0001] The utility model relates to the technical field of forensic evidence detection, in particular to an extraction tool for direct amplification of exfoliated cell DNA. Background Art

[0002] Automated capillary electrophoresis technology and multi-site complex amplification fluorescent STR locus detection technology have greatly improved the detection range of forensic evidence. However, in actual case investigations, due to the nature of the case itself and other factors, it is difficult to find conventional biological samples such as blood spots in some on-site investigations. Therefore, samples that may contain human exfoliated cells have become important evidence for case detection. However, such samples are trace, which is difficult for forensic DNA identification. At the same time, such trace samples are attached to various carriers that come into contact with the human body. Therefore, according to the type of attached carrier, using different extraction tools to extract and test exfoliated cells is a good strategy to improve the extraction rate and utilization rate of trace evidence. However, there is currently a lack of different precise extraction tools for different carriers, which reduces the utilization rate of trace evidence; sometimes, there are usually more trace biological samples that need to be extracted at the scene of the case, and a large number of disposable extraction tools are used, resulting in high economic costs, which is not conducive to cost reduction and efficiency improvement, and more discarded plastics are not conducive to environmental protection; in DNA testing, the existing trace evidence extraction tools generally have to go through the DNA extraction link after collection, which is easy to cause DNA loss and detection failure.

[0003] Therefore, it is necessary to use an extraction tool for direct amplification of exfoliated cell DNA attached to a specific carrier to extract and test trace evidence. Utility Model Content

[0004] In view of the deficiencies in the prior art, the utility model provides an extraction tool for direct amplification of exfoliated cell DNA, which solves the problems mentioned in the above background technology that most DNA extraction tools are disposable, the economic cost is high, and the loss of DNA leads to detection failure.

[0005] To achieve the above purpose, the utility model is implemented through the following technical solutions: an extraction tool for direct amplification of exfoliated cell DNA, including a storage tube, an extraction handle in contact with the storage tube, a hollow tube at the bottom of the extraction handle, a plurality of silica gel microspheres placed inside the hollow tube, a connecting piece is provided on the outer side of the bottom of the hollow tube, a barrier piece is provided at the other end of the connecting piece, when no evidence is extracted, the barrier piece is closed to seal the silica gel microspheres in the hollow tube, a sliding groove is provided inside the extraction handle, a threaded round block is threadedly connected inside the sliding groove, a rotating block is slidably connected inside the threaded round block, and a pushing component is slidably connected between the rotating block and the threaded round block.

[0006] Preferably, a limiting groove is provided on the outer periphery of the rotating block, an elastic component is fixedly connected to the inner side of the limiting groove, a sliding vertical groove is provided inside the threaded round block, a clamping groove is provided on the inner side of the sliding vertical groove, an inner bevel groove is provided inside the threaded round block, a rectangular groove is provided at the bottom of the rotating block, and a silicone pad is fixedly connected to the inner side of the rotating block.

[0007] Preferably, the pushing assembly includes a push rod, the outer periphery of which is slidably connected to the inside of the rotating block and the threaded round block, and the bottom of the push rod is fixedly connected to a push block, the outer periphery of which is slidably connected to the inside of the sliding groove, and when extracting evidence, the push block squeezes the silicone microspheres to cause the barrier sheet to pop open, and half of the silicone microsphere pops out from the bottom of the hollow tube.

[0008] Preferably, the diameter of the top opening of the storage tube is slightly smaller than the outer diameter of the extraction handle, and the contact portion between the interior of the storage tube and the outer periphery of the extraction handle is interference fit.

[0009] Preferably, the silica gel microspheres are insoluble in water, do not deform or swell in water, are non-toxic and tasteless, and have stable chemical properties.

[0010] Preferably, the elastic component includes a limit spring, one end of the limit spring is fixedly connected to the right inner wall of the limit groove, the other end of the limit spring is fixedly connected to the right outer wall of the limit slide bar, the left outer wall of the limit slide bar is set as an arc surface, and the inner wall of the slot fits with the left outer wall of the limit slide bar and is clamped with each other.

[0011] Preferably, the outer periphery of the limiting sliding rod is slidably connected to the inside of the vertical sliding groove, and the outer periphery of the limiting sliding rod is slidably connected to the inside of the limiting groove.

[0012] Preferably, a slope is provided at the bottom of the rotating block, the slope of the bottom surface of the rotating block is slidably connected to the inner wall of the inner slope groove, the rotating block is made of plastic, and the outer side of the silicone cushion is in contact with the outer periphery of the push rod.

[0013] The utility model has the following beneficial effects:

[0014] 1. In the utility model, by providing silica gel microspheres, the DNA extraction step is omitted, the loss of sample during extraction is avoided, and the DNA test is performed by extraction-free direct amplification technology, which makes the test success rate higher, saves time and labor, and at the same time, a push rod is provided so that the DNA extraction equipment can be reused, reducing costs and increasing efficiency, saving economic costs.

[0015] 2. In the utility model, by setting the inner bevel groove, the rotating block is pushed downward, so that the silicone pad contacts the push rod, so that a larger friction force is generated between the push rod and the silicone pad, making it difficult to be touched by accidental operation during operation, thereby preventing the silicone microspheres from falling off. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the overall front three-dimensional structure of the utility model;

[0017] Figure 2 This is a schematic diagram of the front three-dimensional structure of the extraction handle of the utility model;

[0018] Figure 3 This is a schematic diagram of the front cross-sectional three-dimensional structure of the extraction handle of the utility model (the barrier piece is closed);

[0019] Figure 4 This is a schematic diagram of the front cross-sectional three-dimensional structure of the extraction handle of the utility model (the barrier piece is in the open state);

[0020] Figure 5 It is a schematic diagram of the front cross-sectional three-dimensional structure of the rotating block of the utility model.

[0021] Legend:

[0022] 1. Storage tube; 2. Extraction handle; 3. Barrier plate; 4. Hollow tube; 5. Silicone microsphere; 6. Sliding groove; 7. Threaded round block; 8. Rotating block; 9. Push rod; 10. Push block; 11. Limiting groove; 12. Limiting spring; 13. Limiting slide bar; 14. Sliding vertical groove; 15. Card slot; 16. Inner bevel groove; 17. Rectangular groove; 18. Silicone cushion; 19. Connector. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0024] See also Figure 1-Figure 4 The utility model provides an extraction tool for direct amplification of exfoliated cell DNA, comprising a storage tube 1 for protecting the extracted cells from contamination and an extraction handle 2 for convenient holding and operation.

[0025] The extraction handle 2 described above is provided with a sliding groove 6 inside, and an internal thread is provided at the top of the inner wall of the sliding groove 6. The sliding groove 6 is provided with a threaded round block 7, wherein an external thread that matches the internal thread of the sliding groove 6 is provided outside the threaded round block 7, and the threaded round block 7 is fixed in the sliding groove 6 by the internal thread and the external thread. The threaded round block 7 is hollow inside, and a hexagonal prism-shaped rotating block 8 is slidably connected at the top of the threaded round block 7. The hexagonal prism-shaped shape is convenient for handholding and rotating. Relative to the hollow position inside the threaded round block 7, the rotating block 8 is also hollow inside, and a push assembly is slidably connected inside it; the push assembly includes a push rod 9, and the outer periphery of the push rod 9 is slidably connected to the inside of the rotating block 8 and the threaded round block 7 (the push rod 9 passes through the inner hollow positions of the rotating block 8 and the threaded round block 7 from top to bottom respectively). A push block 10 is fixedly connected to the bottom of the push rod 9, and the outer periphery of the push block 10 is slidably connected to the inside of the hollow tube 4, and the hollow tube 4 limits the push block 10 to only move up and down along the inner wall of the hollow tube 4.

[0026] The bottom of the extraction handle 2 described above (i.e., the lower end of the sliding groove 6) is provided with a hollow tube 4, the interior of the hollow tube 4 is a hollow pipe with openings at the top and the bottom, and the interior of the hollow pipe is filled with a plurality of silica gel microspheres; the upper end of the hollow tube 4 is connected to the lower end of the sliding groove 6, and the outer side of the bottom of the hollow tube 4 is connected to the barrier sheet 3 (for example, the barrier sheet 3 can be composed of a plastic sheet with a certain elastic force) through a connecting piece 19, such as Figure 3 or Figure 4 As described, when the barrier sheet 3 pops open, the silicone microsphere 5 pops out, its upper end is connected to the hollow tube, and the lower end is used to collect evidence. The silicone microsphere 5 is insoluble in water, does not deform or swell in water, is non-toxic and tasteless, and has stable chemical properties. The silicone microsphere 5 can absorb human exfoliated epithelial cells attached to a clean and smooth object in an environment with trace amounts of water.

[0027] The storage tube 1 described above is provided with a cavity, and the upper end of the cavity is open; the extraction handle 2 is inserted into the cavity in the storage tube 1 from the upper end of the cavity. The diameter of the upper end of the cavity of the storage tube 1 is slightly smaller than the outer diameter of the extraction handle 2, and the contact part between the inner cavity of the storage tube 1 and the outer periphery of the extraction handle 2 is interference fit so that the extraction handle 2 and the storage tube 1 are fixed and sealed. The hollow tube 4 is sealed and stored in the inner cavity of the storage tube 1 through the extraction handle 2.

[0028] like Figure 3-Figure 5As shown, the outer periphery of the rotating block 8 described above is provided with a limiting groove 11, and the limiting groove 11 is provided with four groups, which are evenly distributed in a ring shape on the outer periphery of the rotating block 8. An elastic component is fixedly connected to the inner side of the limiting groove 11, and the elastic component includes a limiting spring 12 (the limiting spring 12 can also be some other materials with elastic deformation ability) and a limiting slide bar 13. One end of the limiting spring 12 is fixedly connected to the right inner wall of the limiting groove 11, and the other end of the limiting spring 12 is fixedly connected to the right outer wall of the limiting slide bar 13. When the limiting slide bar 13 is not subjected to force, the limiting spring 12 will push the limiting slide bar 13 to move outward. The outer periphery of the slide bar 13 is slidably connected to the inside of the limit groove 11, and the outer wall on the left side of the limit slide bar 13 is set to an arc surface, which can convert part of the force applied to the limit slide bar 13 in the vertical direction into the horizontal direction; a sliding vertical groove 14 is opened inside the threaded round block 7, and the outer periphery of the limit slide bar 13 is slidably connected to the inside of the sliding vertical groove 14. The sliding vertical groove 14 limits the limit slide bar 13 to only slide up and down along the sliding vertical groove 14. A clamping groove 15 is opened on the inner side of the sliding vertical groove 14. The clamping groove 15 is provided with two groups, which are symmetrically arranged on the upper and lower sides of the sliding vertical groove 14. The inner wall of the clamping groove 15 fits with the outer wall on the left side of the limit slide bar 13 and is clamped with each other.

[0029] The rotating block 8 is made of plastic, and a rectangular groove 17 is provided at the bottom of the rotating block 8. There are four groups of rectangular grooves 17, which are evenly distributed in a ring shape at the bottom of the rotating block 8, so that the bottom of the rotating block 8 can be partially deformed when subjected to pressure. An inner bevel groove 16 is provided inside the threaded round block 7, and an inclined surface is provided at the bottom of the rotating block 8. The inclined surface at the bottom of the rotating block 8 is slidably connected to the inner wall of the inner bevel groove 16. When the rotating block 8 moves downward, the bottom of the rotating block 8 and the inner bevel groove 16 slide downward and tighten along the conical surface. A silicone pad 18 is fixedly connected to the inside of the rotating block 8, and the outer side of the silicone pad 18 is in contact with the outer periphery of the push rod 9. The friction coefficient between the silicone pad 18 and the push rod 9 is high, and a large friction force will be generated when subjected to force.

[0030] Working principle: When you want to use the device of the utility model to extract DNA, hold the storage tube 1 with one hand and the extraction handle 2 with the other hand, take out the extraction handle 2, turn the push rod 9 to squeeze out half of the silicone microsphere 5 from the hollow tube 4, dip the half of the silicone microsphere 5 that pops out of the hollow tube 4 into clean distilled water, hold the extraction handle 2, place the silicone microsphere 5 on the suspected part containing exfoliated epithelial cells, wipe it with moderate force, and after wiping, put the extraction part back into the storage tube 1 to complete the sample collection. In the DNA laboratory, take out the extraction handle 2, align the silicone microsphere 5 with the plastic conical tube containing PCR reagents, and turn the push rod again. The rod 9 squeezes the entire silicone microsphere 5 out of the hollow tube 4, and the silicone microsphere 5 sinks into the PCR reagent to complete the sample addition. At this time, the rotating block 8 is rotated, and the rotating block 8 drives the threaded round block 7 to rotate, so that the threaded round block 7 is out of contact with the extraction handle 2, and then some silicone microspheres 5 are filled into the extraction handle 2. When the rotating block 8 is rotated, the threaded round block 7 is reconnected with the extraction handle 2, and the push rod 9 is pushed downward, and the push rod 9 pushes the push block 10, and the push block 10 squeezes the silicone microsphere 5, and the silicone microsphere 5 is squeezed out through the inside of the hollow tube 4, and fixed in the inside of the hollow tube 4 through the barrier sheet 3, so as to facilitate repeated use and reduce costs and increase efficiency. When performing the DNA extraction operation, to prevent the push rod 9 from being accidentally touched and causing the silicone microsphere 5 to disengage, the rotating block 8 is pressed downward, and the rotating block 8 drives the limit slide bar 13 downward. The outer arc surface of the limit slide bar 13 converts part of the vertical force into a horizontal force, so that the limit slide bar 13 compresses the limit spring 12 and moves to the inside of the limit groove 11, and breaks contact with the upper card groove 15. When the limit slide bar 13 slides to the lower card groove 15, the limit spring 12 releases the compression and pushes the limit slide bar 13 to engage with the card groove 15. At this time, the bottom surface of the rotating block 8 moves downward along the inner inclined groove 16, and the bottom of the rotating block 8 is tightened along the inclined surface to produce deformation, so that a large friction force is generated between the silicone cushion 18 and the limit slide bar 13, thereby preventing accidental touch.

[0031] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An extraction tool for direct amplification of exfoliated cell DNA, comprising a storage tube (1), Features: The storage tube (1) is provided with an extraction handle (2) inside; The bottom of the extraction handle (2) is provided with a hollow tube (4), the interior of the hollow tube (4) is a hollow pipe, and a plurality of silica microspheres (5) are placed therein; the outer side of the bottom of the hollow tube (4) is a connecting piece (19), and the other end of the connecting piece (19) is provided with a barrier sheet (3); The extraction handle (2) is provided with a sliding groove (6), a threaded round block (7) is arranged in the sliding groove (6), a rotating block (8) is slidably connected inside the threaded round block (7), and a pushing component is slidably connected inside the rotating block (8) and the threaded round block (7).

2. An extraction tool for direct amplification of exfoliated cell DNA according to claim 1, Features: The outer periphery of the rotating block (8) is provided with a limiting groove (11), and an elastic component is fixedly connected to the inner side of the limiting groove (11); a rectangular groove (17) is provided at the bottom of the rotating block (8); a silicone soft pad (18) is fixedly connected to the inside of the rotating block (8) A vertical sliding groove (14) is provided inside the threaded round block (7), and a clamping groove (15) is provided inside the vertical sliding groove (14); an inner bevel groove (16) is provided inside the threaded round block (7).

3. An extraction tool for direct amplification of exfoliated cell DNA according to claim 1, Features: The pushing assembly comprises a push rod (9); the outer periphery of the push rod (9) is slidably connected to the inside of the rotating block (8) and the threaded round block (7); a push block (10) is fixedly connected to the bottom of the push rod (9), and the outer periphery of the push block (10) is slidably connected to the inside of the hollow tube (4).

4. The extraction tool for direct amplification of exfoliated cell DNA according to claim 1, Features: The diameter of the top opening of the storage tube (1) is slightly smaller than the outer diameter of the extraction handle (2), and the contact portion between the interior of the storage tube (1) and the outer periphery of the extraction handle (2) is interference fit.

5. The extraction tool for direct amplification of exfoliated cell DNA according to claim 1, Features: The silica gel microspheres (5) are made of a silica gel material that is insoluble in water, does not deform or swell in water, is non-toxic and tasteless, and has stable chemical properties.

6. The extraction tool for direct amplification of exfoliated cell DNA according to claim 2, Features: The elastic component comprises a limit spring (12) and a limit sliding rod (13); One end of the limit spring (12) is fixedly connected to the right inner wall of the limit groove (11), and the other end of the limit spring (12) is fixedly connected to the right outer wall of the limit slide bar (13). The left outer wall of the limit slide bar (13) is set as an arc surface, and the inner wall of the clamping groove (15) fits with the left outer wall of the limit slide bar (13) and is clamped with each other.

7. The extraction tool for direct amplification of exfoliated cell DNA according to claim 6, Features: The outer periphery of the limiting sliding rod (13) is slidably connected to the interior of the vertical sliding groove (14), and the outer periphery of the limiting sliding rod (13) is slidably connected to the interior of the limiting groove (11).

8. The extraction tool for direct amplification of exfoliated cell DNA according to claim 2, Features: The bottom of the rotating block (8) is provided with an inclined surface, and the inclined surface of the bottom of the rotating block (8) is slidably connected to the inner wall of the inner inclined surface groove (16). The rotating block (8) is made of plastic, and the outer side of the silicone soft pad (18) is in contact with the outer periphery of the push rod (9).

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