CN219951016U

CN219951016U - Nucleic acid extraction tube

Info

Publication number: CN219951016U
Application number: CN202320603529.7U
Authority: CN
Inventors: 沙海天; 章杰青; 夏龚杰; 白艳军
Original assignee: Shanghai Wanzijian Biotechnology Co ltd
Current assignee: Shanghai Wanzijian Biotechnology Co ltd
Priority date: 2023-03-24
Filing date: 2023-03-24
Publication date: 2023-11-03
Anticipated expiration: 2033-03-24

Abstract

The utility model relates to the technical field of nucleic acid detection, in particular to a nucleic acid extraction tube, which comprises: the inner pipe body is hollow to form a reaction cabin, the reaction cabin is used for containing reaction liquid, an opening for injecting the reaction liquid is formed in the top of the reaction cabin, and an inner inlet and outlet are formed in the bottom of the reaction cabin; the outer pipe body is hollow to form an inner cabin, the top of the inner cabin is provided with an opening, the bottom of the inner cabin is provided with an outlet, and the outlet is used for introducing reaction liquid or discharging waste liquid; the bottom of the inner pipe body is inserted into the inner cabin from the opening, and the inner pipe body can move relative to the outer pipe body, so that the inner inlet and the outer inlet are communicated or not communicated. The nucleic acid extraction reaction and the waste liquid discharge can be completed in the nucleic acid extraction tube under the condition that the disposable suction head is not used, so that the problem that the disposable suction head is required to be frequently used in the automatic nucleic acid extraction process is solved; can be matched with an automatic nucleic acid extractor to realize automatic pipelining tubular nucleic acid extraction, and solves the problem of automatic pipelining of tubular nucleic acid extraction.

Description

Nucleic acid extraction tube

Technical Field

The utility model relates to the technical field of nucleic acid detection, in particular to a nucleic acid extraction tube.

Background

Nucleic acid detection is a method for directly detecting genetic materials such as DNA or RNA in a biological sample, and is often used in-vitro diagnosis projects such as diagnosis of genetic diseases, early screening of tumors, target confirmation of targeted drug administration, confirmation of pathogenic microorganism infection and the like.

The basis of nucleic acid detection is to obtain high-quality nucleic acid, and the methods for extracting and purifying nucleic acid are numerous. At present, the usual methods for nucleic acid extraction are: phenol chloroform, magnetic bead, column, etc., and methods that facilitate automation of nucleic acid extraction include column and magnetic bead methods. The implementation of nucleic acid extraction automation not only depends on the convenience of methodology, but also requires the design of matched extraction consumables according to requirements.

The existing matched automatic nucleic acid extractor is used for extracting consumable materials for realizing nucleic acid extraction, the problem that the disposable suction head is required to be frequently used for sucking out nucleic acid extraction reaction waste liquid in the automatic nucleic acid extraction process exists, the consumable material usage amount is large, the consumable materials are required to be stored in the nucleic acid extractor equipment in a large area, and the nucleic acid extractor is large in size.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, the present utility model is to provide a nucleic acid extraction tube, which can be used with an automatic nucleic acid extractor to realize automatic pipelined nucleic acid extraction without sucking waste liquid with a disposable suction head.

In order to solve the technical problems, the utility model adopts the following technical scheme:

the present utility model provides a nucleic acid extraction tube comprising: the inner pipe body is hollow to form a reaction cabin, the reaction cabin is used for containing reaction liquid, an opening for injecting the reaction liquid is formed in the top of the reaction cabin, and an inner inlet and outlet are formed in the bottom of the reaction cabin; the outer pipe body is hollow to form an inner cabin, the top of the inner cabin is provided with an opening, the bottom of the inner cabin is provided with an outlet, and the outlet is used for introducing reaction liquid or discharging waste liquid; the bottom of the inner pipe body is inserted into the inner cabin from the opening, and the inner pipe body can move relative to the outer pipe body, so that the inner inlet and the outer inlet are communicated or not communicated.

Preferably, the inner pipe body is rotatably inserted into the inner cabin of the outer pipe body, and the inner inlet and the outer inlet are communicated or not communicated by rotating the inner pipe body.

Preferably, the inner inlet and outlet are positioned at the bottom end of the inner pipe body, the outer inlet is positioned at the bottom end of the outer pipe body, the bottom of the inner pipe body is inserted to the bottom of the inner cabin, and the outer surface of the bottom end of the inner pipe body is attached to the inner surface of the bottom end of the outer pipe body.

Preferably, the bottom end of the outer tube body is an inverted cone bottom end, and the outlet inlet is a passage penetrating through the top and bottom surfaces of the inverted cone bottom end.

Preferably, a limiting structure is arranged between the inner pipe body and the outer pipe body, the limiting structure is used for limiting the inner pipe body after the inner pipe body rotates by a specified angle, so that the inner pipe body is fixed with the outer pipe body, and when the inner pipe body rotates by the specified angle, the communication state of the inner inlet and the outer inlet is switched between being communicated and not communicated.

Preferably, the limit structure comprises a limit boss arranged on the outer peripheral surface of the inner pipe body and a limit clamping groove arranged on the inner peripheral surface of the outer pipe body, and the limit boss is in clamping fit with the limit clamping groove.

Preferably, two limit bosses which are symmetrically arranged are arranged on the outer circumferential surface of the inner pipe body along the circumferential direction at intervals, four limit clamping grooves are uniformly arranged on the inner circumferential surface of the outer pipe body along the circumferential direction at intervals, and the two limit bosses are respectively matched with the two opposite limit clamping grooves in a clamping way.

Preferably, a sealing structure is arranged between the inner pipe body and the outer pipe body and is positioned above the inner inlet and outlet.

Preferably, the sealing structure comprises a sealing groove arranged on the outer peripheral surface of the inner pipe body and a sealing ring arranged on the inner peripheral surface of the outer pipe body, and the sealing ring is embedded in the sealing groove.

Preferably, the outer peripheral surface of the outer tube body is provided with a fixing part, and the fixing part is used for being connected with an air pump tube or a mechanical arm of the automatic nucleic acid extraction instrument.

Compared with the prior art, the utility model has obvious progress:

the nucleic acid extraction tube adopts a relatively movable combined structure of the inner tube body and the outer tube body, the communication state between the inner inlet and the outer inlet at the bottom of the reaction chamber of the inner tube body and the communication state between the inner inlet and the outer inlet at the bottom of the inner chamber of the outer tube body can be switched between communication and non-communication, the nucleic acid extraction reaction can be carried out in the reaction chamber when the inner inlet and the outer inlet are not communicated, and the reaction liquid can be introduced into the reaction chamber or the waste liquid in the reaction chamber can be discharged through the outer inlet when the inner inlet and the outer inlet are communicated, so that the nucleic acid extraction reaction and the waste liquid discharge can be completed in the nucleic acid extraction tube without using a disposable suction head, the problem that the disposable suction head is required to be frequently used in the existing automatic nucleic acid extraction process is solved, the consumption of extraction materials can be effectively reduced, the area for storing the extraction materials in the nucleic acid extraction instrument equipment is reduced, and the volume of the automatic nucleic acid extraction instrument is reduced. The nucleic acid extraction tube can complete nucleic acid extraction reaction and waste liquid discharge, so that the nucleic acid extraction tube can be matched with an automatic nucleic acid extractor to realize automatic pipelining tubular nucleic acid extraction, and the problem of automatic pipelining of tubular nucleic acid extraction is solved.

Drawings

FIG. 1 is a schematic perspective view of a nucleic acid extraction tube according to an embodiment of the present utility model.

FIG. 2 is a schematic front view of a nucleic acid extraction tube according to an embodiment of the present utility model.

Fig. 3 is a schematic cross-sectional view taken along A-A in fig. 2.

FIG. 4 is a schematic perspective view of an inner tube in a nucleic acid isolation tube according to an embodiment of the present utility model.

FIG. 5 is a schematic front view of an inner tube in a nucleic acid isolation tube according to an embodiment of the present utility model.

Fig. 6 is a schematic cross-sectional view taken along B-B in fig. 5.

FIG. 7 is a schematic perspective view of an outer tube in a nucleic acid isolation tube according to an embodiment of the present utility model.

FIG. 8 is a schematic front view of an outer tube in a nucleic acid isolation tube according to an embodiment of the present utility model.

Fig. 9 is a schematic cross-sectional view taken along the direction C-C in fig. 8.

Wherein reference numerals are as follows:

1. inner pipe body

10. Reaction cabin

11. An opening

12. Inner entrance

13. Spacing boss

14. Sealing groove

2. Outer tube body

20. Inner cabin

21. Open mouth

22. Egress and ingress

23. Limiting clamping groove

24. Sealing ring

25. Fixing part

Detailed Description

The following describes the embodiments of the present utility model in further detail with reference to the accompanying drawings. These embodiments are merely illustrative of the present utility model and are not intended to be limiting.

In the description of the present utility model, it should be noted that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present utility model and simplifying the description, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present utility model, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

Furthermore, in the description of the present utility model, unless otherwise indicated, the meaning of "a plurality" is two or more.

As shown in FIGS. 1 to 9, one embodiment of the nucleic acid extraction tube of the present utility model. The nucleic acid isolation tube of the present embodiment includes an inner tube body 1 and an outer tube body 2. The inner tube body 1 is hollow to form a reaction chamber 10, the reaction chamber 10 is used for containing reaction liquid for nucleic acid extraction reaction, and waste liquid is formed after the nucleic acid extraction reaction is finished. The top of the reaction chamber 10 is provided with an opening 11 for injecting the reaction liquid, and the opening 11 is preferably located at the top end of the inner tube body 1. An inner inlet and outlet 12 is provided at the bottom of the reaction chamber 10. The outer tube 2 is hollow to form an inner chamber 20, and the inner chamber 20 is used for placing the inner tube 1. The top of the inner compartment 20 is provided with an opening 21, the opening 21 being for insertion of the inner tubular body 1, the opening 21 preferably being located at the top end of the outer tubular body 2. The bottom of the inner chamber 20 is provided with an outlet 22, the outlet 22 is used for introducing reaction liquid or discharging waste liquid, and the outlet 22 can be connected with a liquid supply pipeline or a liquid discarding pipeline on the automatic nucleic acid extractor so as to realize liquid suction or liquid discarding of the outlet 22. The bottom of the inner pipe body 1 is inserted into the inner compartment 20 from the opening 21 in the outer pipe body 2, and the inner pipe body 1 is movable relative to the outer pipe body 2 so that the inner inlet and outlet 12 is in communication with or out of communication with the outer inlet 22. The inner pipe body 1 moves relative to the outer pipe body 2 in the outer pipe body 2, so that the communication state between the inner inlet and outlet 12 and the outer inlet 22 is switched between communication and non-communication. When the inner inlet/outlet 12 communicates with the outer inlet/outlet 22, the outer inlet/outlet 22 communicates with the reaction chamber 10 through the inner inlet/outlet 12, and the reaction solution can be introduced into the reaction chamber 10 through the outer inlet/outlet 22, or the waste solution in the reaction chamber 10 can be discharged through the outer inlet/outlet 22. When the inner inlet/outlet 12 is not connected to the outer inlet/outlet 22, the outer tube 2 closes the inner inlet/outlet 12, and the reaction solution can be blocked in the reaction chamber 10, so that the nucleic acid extraction reaction can be performed in the reaction chamber 10.

The nucleic acid extraction tube of this embodiment adopts the relatively movable combined structure of the inner tube body 1 and the outer tube body 2, through the activity of the inner tube body 1 in the outer tube body 2, the communication state of the inner inlet and outlet 12 at the bottom of the reaction chamber 10 of the inner tube body 1 and the communication state of the outer inlet and outlet 22 at the bottom of the inner chamber 20 of the outer tube body 2 can be switched between being communicated and not communicated, the nucleic acid extraction reaction can be performed in the reaction chamber 10 when the inner inlet and outlet 12 is not communicated with the outer inlet and outlet 22, and the reaction solution can be introduced into the reaction chamber 10 or the waste solution in the reaction chamber 10 can be discharged through the outer inlet and outlet 22 when the inner inlet and outlet 12 is communicated with the outer inlet and outlet 22, so that the nucleic acid extraction reaction and the waste solution discharge can be completed in the nucleic acid extraction tube without using the disposable suction head, the problem that the disposable suction head is required frequently used in the existing automatic nucleic acid extraction process can be solved, the consumption of extraction materials can be effectively reduced, the area for storing the extraction materials in the nucleic acid extraction instrument equipment can be reduced, and the volume of the automatic nucleic acid extraction instrument can be reduced. The nucleic acid extraction tube of the embodiment can complete nucleic acid extraction reaction and waste liquid discharge, so that the nucleic acid extraction tube can be matched with an automatic nucleic acid extractor to realize automatic pipelining tubular nucleic acid extraction, and the problem of automatic pipelining of tubular nucleic acid extraction is solved.

In the process of performing automatic nucleic acid extraction by using the automatic nucleic acid extractor for nucleic acid extraction tube according to this embodiment, in order to prevent contamination of the reaction solution, the outlet 22 at the bottom of the inner chamber 20 of the outer tube 2 is only used for sucking liquid to introduce the reaction solution into the reaction chamber 10 of the inner tube 1 when it is first used, and in the subsequent process of performing nucleic acid extraction by flowing water, the outlet 22 is used for discarding the liquid to discharge the waste liquid in the reaction chamber 10, and the reaction solution is injected into the reaction chamber 10 from the opening 11 at the top of the reaction chamber 10. The reaction solution includes a sample and a nucleic acid extraction reagent, which are introduced into the reaction chamber 10 from the outlet 22 and the opening 11, respectively, when they are used for the first time, and then introduced into the reaction chamber 10 from the opening 11.

In this embodiment, the inner pipe 1 is preferably in a rotating fit manner with respect to the outer pipe 2, the inner pipe 1 is rotatably inserted into the inner chamber 20 of the outer pipe 2, and the inner inlet and outlet 12 is communicated with or not communicated with the outer inlet and outlet 22 by rotating the inner pipe 1.

Preferably, referring to fig. 3, 6 and 9, the inner inlet and outlet 12 is located at the bottom end of the inner tube 1, and the inner inlet and outlet 12 penetrates up and down through the inner surface of the bottom end of the inner tube 1 and the outer surface of the bottom end of the inner tube 1, and the inner surface of the bottom end of the inner tube 1 is also the bilge wall surface of the reaction chamber 10 of the inner tube 1; the outlet 22 is positioned at the bottom end of the outer pipe body 2, the outlet 22 vertically penetrates through the inner surface of the bottom end of the outer pipe body 2 and the outer surface of the bottom end of the outer pipe body 2, and the inner surface of the bottom end of the outer pipe body 2 is also the bilge wall surface of the inner cabin 20 of the outer pipe body 2; the bottom of the inner pipe body 1 is inserted to the bottom of the inner cabin 20 of the outer pipe body 2, and the outer surface of the bottom end of the inner pipe body 1 is attached to the inner surface of the bottom end of the outer pipe body 2. The outer surface of the bottom end of the inner pipe body 1 is attached to the inner surface of the bottom end of the outer pipe body 2, so that the reaction liquid can be prevented from flowing between the inner pipe body 1 and the outer pipe body 2 when the inner inlet and outlet 12 is communicated with the outer inlet 22 or not, and the sealing effect is achieved.

In this embodiment, the inner tube 1 and the outer tube 2 are coaxially arranged, so that the inner inlet and outlet 12 and the outer inlet 22 can be staggered and not communicated when the inner tube 1 rotates, the inner inlet and outlet 12 is arranged at a central position avoiding the bottom end of the inner tube 1, and the outer inlet 22 is also arranged at a central position avoiding the bottom end of the outer tube 2; in order to allow the inner port 12 to overlap and communicate with the outer inlet 22 when the inner tube body 1 is rotated, the axis of the inner port 12 and the axis of the outer inlet 22 are located on the same circumference.

Further, in this embodiment, the bottom end of the outer tube 2 is an inverted cone-shaped bottom end, the outlet 22 is a passage penetrating the top surface and the bottom surface of the inverted cone-shaped bottom end of the outer tube 2 up and down, and the top surface of the inverted cone-shaped bottom end of the outer tube 2 is the inner surface of the bottom end of the outer tube 2 and is also the bilge wall surface of the inner cabin 20 of the outer tube 2. The bottom end of the outer tube body 2 is of an inverted cone shape, which is favorable for connecting the outlet and inlet 22 with a liquid supply pipeline or a liquid discarding pipeline on the automatic nucleic acid extraction instrument, so as to realize liquid suction or liquid discarding of the outlet and inlet 22. When the bottom end of the outer tubular body 2 is an inverted cone-shaped bottom end, the outlet and inlet 22 is a passage inclined up and down, and in this case, the axis of the inner inlet and outlet 12 and the axis of the outlet and inlet 22 are located on the same circumference, which means that the axis of the inner inlet and outlet 12 and the axis of the port of the passage located on the top surface of the inverted cone-shaped bottom end are located on the same circumference.

In this embodiment, preferably, a limit structure is disposed between the inner tube 1 and the outer tube 2, and the limit structure is used for limiting the inner tube 1 after the inner tube 1 rotates by a specified angle, so that the inner tube 1 is fixed to the outer tube 2, when the inner tube 1 rotates by a specified angle, the communication state of the inner inlet 12 and the outer inlet 22 is switched between being communicated and not communicated, and the inner tube 1 is positioned in the outer tube 2 through the limit structure, so that the state that the inner inlet 12 and the outer inlet 22 are communicated or not communicated is maintained, and the nucleic acid extraction reaction and the waste liquid discharge can be performed independently.

Referring to fig. 1, 4 and 7, in a preferred embodiment, the limiting structure includes a limiting boss 13 and a limiting slot 23, the limiting boss 13 is disposed on the outer peripheral surface of the inner tube body 1, the limiting slot 23 is disposed on the inner peripheral surface of the outer tube body 2, and the inner peripheral surface of the outer tube body 2 is also the inner peripheral wall surface of the inner compartment 20 of the outer tube body 2. The limit boss 13 is matched with the limit clamping groove 23 in a clamping way, so that the inner pipe body 1 and the outer pipe body 2 are positioned in the circumferential direction and fixed with each other. When the inner pipe body 1 is rotated, the limiting boss 13 can be separated from the limiting clamping groove 23 under the action of external force, so that the inner pipe body 1 can rotate relative to the outer pipe body 2. Preferably, two symmetrically arranged limit bosses 13 are arranged on the outer peripheral surface of the inner pipe body 1 at intervals along the circumferential direction, namely, the two limit bosses 13 are oppositely arranged on the outer peripheral surface of the inner pipe body 1 along the radial direction, four limit clamping grooves 23 are uniformly arranged on the inner peripheral surface of the outer pipe body 2 at intervals along the circumferential direction, two pairs of limit clamping grooves 23 which are oppositely arranged along the radial direction and are crisscrossed are formed on the outer peripheral surface of the inner pipe body 1, and the two limit bosses 13 are respectively matched with the two opposite limit clamping grooves 23 in a clamping manner. When the two limiting bosses 13 are in clamping fit with the pair of limiting clamping grooves 23, the inner inlet and outlet 12 is communicated with the outlet and inlet 22, and when the two limiting bosses 13 are in clamping fit with the other pair of limiting clamping grooves 23, the inner inlet and outlet 12 is not communicated with the outlet and inlet 22. Therefore, when the inner pipe body 1 is rotated by 90 degrees in the forward and reverse directions, the communication state of the inner inlet and outlet 12 and the outer inlet 22 can be switched back and forth between being communicated and not communicated, and the limit fixation of the inner pipe body 1 and the outer pipe body 2 before and after rotation can be realized.

In this embodiment, preferably, a sealing structure is disposed between the inner tube 1 and the outer tube 2, and the sealing structure is located above the inner inlet and outlet 12 at the bottom of the reaction chamber 10 of the inner tube 1, so as to prevent the reaction solution from flowing into the space between the inner tube 1 and the outer tube 2, thereby achieving a sealing effect, and particularly when the inner inlet and outlet 12 is not communicated with the outer inlet 22, the sealing structure and the outer tube 2 can ensure the sealing of the inner inlet and outlet 12, so as to ensure that the reaction solution is blocked in the reaction chamber 10, so as to ensure the effective progress of the nucleic acid extraction reaction.

Referring to fig. 3, 5 and 9, in a preferred embodiment, the sealing structure includes a sealing groove 14 and a sealing ring 24, the sealing groove 14 is disposed on the outer circumferential surface of the inner tube body 1, the sealing groove 14 is an annular groove extending along the circumferential direction of the inner tube body 1, the sealing ring 24 is disposed on the inner circumferential surface of the outer tube body 2, the sealing ring 24 is an annular sealing ring extending along the circumferential direction of the outer tube body 2, and the sealing ring 24 is embedded in the sealing groove 14.

Referring to fig. 7 to 9, in the present embodiment, it is preferable that a fixing portion 25 is provided on the outer circumferential surface of the outer tube 2, the fixing portion 25 being for connecting an air pump tube or a robot arm of the automated nucleic acid extracting apparatus. The suction or blowing of air at the opening 11 at the top of the reaction chamber 10 of the inner pipe body 1 through the air pump pipe can control the liquid suction or liquid discarding in the reaction chamber 10 through the inner inlet and outlet 12 and the outer inlet 22 which are communicated. The nucleic acid extraction tube can be sequentially transferred between the operation stations along the production line in the process of automatically and continuously extracting the nucleic acid by the mechanical arm. Preferably, the fixing portion 25 is an annular boss provided on the top outer peripheral surface of the outer tube body 2.

The foregoing is merely a preferred embodiment of the present utility model, and it should be noted that modifications and substitutions can be made by those skilled in the art without departing from the technical principles of the present utility model, and these modifications and substitutions should also be considered as being within the scope of the present utility model.

Claims

1. A nucleic acid extraction tube, comprising:

the inner tube body (1) is hollow to form a reaction cabin (10), the reaction cabin (10) is used for containing reaction liquid, an opening (11) for injecting the reaction liquid is formed in the top of the reaction cabin (10), and an inner inlet and outlet (12) is formed in the bottom of the reaction cabin (10);

the device comprises an outer pipe body (2), wherein an inner cabin (20) is formed in the inner part in a hollow mode, an opening (21) is formed in the top of the inner cabin (20), an outlet inlet (22) is formed in the bottom of the inner cabin (20), and the outlet inlet (22) is used for introducing reaction liquid or discharging waste liquid; the bottom of the inner pipe body (1) is inserted into the inner cabin (20) from the opening (21), and the inner pipe body (1) can move relative to the outer pipe body (2) so that the inner inlet and outlet (12) is communicated with or not communicated with the outer inlet and outlet (22).

2. The nucleic acid extraction tube according to claim 1, characterized in that the inner tube (1) is rotatably inserted into the inner compartment (20) of the outer tube (2), and the inner inlet and outlet (12) is brought into communication with or out of communication with the outer inlet (22) by rotating the inner tube (1).

3. The nucleic acid extraction tube according to claim 2, characterized in that the inner inlet (12) is located at the bottom end of the inner tube body (1), the outer inlet (22) is located at the bottom end of the outer tube body (2), and the bottom of the inner tube body (1) is inserted into the bottom of the inner compartment (20) so that the outer surface of the bottom end of the inner tube body (1) is bonded to the inner surface of the bottom end of the outer tube body (2).

4. A nucleic acid extraction tube according to claim 3, characterized in that the bottom end of the outer tube (2) is an inverted conical bottom end and the outlet inlet (22) is a passage through the top and bottom surfaces of the inverted conical bottom end.

5. The nucleic acid extraction tube according to claim 2, characterized in that a limit structure is provided between the inner tube body (1) and the outer tube body (2), the limit structure is used for limiting the inner tube body (1) after the inner tube body (1) rotates by a specified angle, so that the inner tube body (1) is fixed with the outer tube body (2), and when the inner tube body (1) rotates by the specified angle, the communication state between the inner inlet (12) and the outer inlet (22) is switched between being communicated and not being communicated.

6. The nucleic acid extraction tube according to claim 5, wherein the limit structure comprises a limit boss (13) provided on the outer peripheral surface of the inner tube body (1) and a limit clamping groove (23) provided on the inner peripheral surface of the outer tube body (2), and the limit boss (13) is in clamping fit with the limit clamping groove (23).

7. The nucleic acid extraction tube according to claim 6, wherein two limit bosses (13) are circumferentially arranged at intervals on the outer peripheral surface of the inner tube body (1), four limit clamping grooves (23) are circumferentially arranged at intervals on the inner peripheral surface of the outer tube body (2), and the two limit bosses (13) are respectively in clamping fit with the two opposite limit clamping grooves (23).

8. The nucleic acid extraction tube according to claim 1, characterized in that a sealing structure is provided between the inner tube body (1) and the outer tube body (2), the sealing structure being located above the inner inlet/outlet (12).

9. The nucleic acid extraction tube according to claim 8, characterized in that the sealing structure comprises a sealing groove (14) provided on an outer peripheral surface of the inner tube body (1) and a sealing ring (24) provided on an inner peripheral surface of the outer tube body (2), the sealing ring (24) being embedded in the sealing groove (14).

10. The nucleic acid extraction tube according to claim 1, characterized in that a fixing portion (25) is provided on the outer peripheral surface of the outer tube (2), the fixing portion (25) being used for connecting an air pump tube or a mechanical arm of an automated nucleic acid extraction instrument.