A nucleic acid extraction device

Abstract

The application relates to the field of nucleic acid detection, in particular to a nucleic acid extraction device which comprises a test tube, a magnetic bead adsorption cavity, a washing cavity and an elution cavity are sequentially arranged in the test tube, a magnetic rod channel extending between the magnetic bead adsorption cavity, the washing cavity and the elution cavity is further arranged in the test tube, a magnetic rod inlet for the magnetic rod to enter is formed at one end of the magnetic rod channel, a driving mechanism and a magnetic rod are further arranged, the magnetic rod can extend into the test tube from the magnetic rod inlet, the magnetic rod comprises a screw rod and a magnet screw-connected on the screw rod, the magnet is locked in the circumferential direction after entering the magnetic rod channel, and the driving mechanism is used for driving the relative rotation between the screw rod and the magnet, so that the magnet moves linearly on the screw rod and moves the magnetic beads from the magnetic bead adsorption cavity to the elution cavity. The magnet is arranged on the screw rod and moves on the screw rod to drive the magnetic beads to move in the test tube, the whole magnetic rod does not need to be moved, the stroke is shortened, and the magnet moves on the screw rod, so that the position of the magnet is convenient to control.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of nucleic acid detection, and particularly to a nucleic acid extraction device. BACKGROUND

[0002] With the rapid development of genetic diagnosis, transgenic food detection and personalized medicine, the current nucleic acid extraction technology cannot meet the needs of today's biotechnology, and there is an urgent need for high-throughput and automated nucleic acid extraction methods. Under this background, magnetic bead method nucleic acid extraction emerged as the times require. The magnetic bead method nucleic acid extraction can generally be divided into four steps: lysis, binding, washing and elution, which is simple to operate and time-saving. The whole extraction process can be completed within 36-40 minutes, and the specific binding of magnetic beads and nucleic acids makes the extracted nucleic acids have high purity and large concentration. In addition, since no toxic reagents such as benzene and chloroform are used in the traditional method, the harm to the experimental operators is minimized, which meets the modern environmental protection concept.

[0003] The applicant disclosed an integrated lower opening nucleic acid fast extraction test tube, a fast extraction detection device and method in the Chinese invention patent application (publication number: CN113186098A, publication date: 2021.07.30), wherein the test tube comprises a main tube; a lysis zone, a washing zone and an elution zone are sequentially arranged in the internal cavity of the main tube from top to bottom; a hydrophobic sealing layer is arranged between the lysis zone and the washing zone and between the washing zone and the elution zone to separate them, and magnetic bead washing liquid and nucleic acid elution liquid are respectively arranged in the washing zone and the elution zone; the internal cavity of the main tube is further provided with a magnetic track extending from the lysis zone to the elution zone, the lower end of the magnetic track is integrally formed with the main tube and is provided with an opening connected with the outside for the magnetic rod to extend into, and the upper end of the magnetic track is closed and located in the elution zone. In use, the magnetic rod is extended into the magnetic track, and the magnetic beads are moved from the lysis zone to the lower elution zone by magnetic force, so as to transfer the nucleic acids combined with the magnetic beads in the lysis zone to the elution zone for subsequent detection.

[0004] However, the applicant found that the test tube has the following problems in the process of using the above-mentioned test tube: in order to move the magnetic beads in the test tube, the magnetic rod needs to be moved in the magnetic rod channel, and for the magnetic rod structure in the prior art, the magnetic rod needs to be inserted into the test tube and then moved outward, which requires a large stroke for the magnetic rod, which is not conducive to the miniaturization of the detection device. In addition, since the magnetic rod has a large length and the gap between the magnetic rod and the magnetic rod channel is usually small, it is not easy to control the movement of the magnetic rod. For example, the magnetic rod is easy to collide with the magnetic rod channel when moving in the magnetic rod channel. SUMMARY

[0005] To address the aforementioned problems, the present invention aims to provide a nucleic acid extraction device that, by placing a magnet on a screw, moves the magnet along the screw, thereby moving a magnetic bead within the test tube. This eliminates the need to move the entire magnetic rod, shortening the travel distance. Furthermore, the way the magnet moves along the screw facilitates control over its position.

[0006] To achieve the objectives of this invention, the following technical solutions are adopted:

[0007] A nucleic acid extraction device includes: a test tube, in which a magnetic bead adsorption chamber, a washing chamber, and an elution chamber are sequentially arranged; the washing chamber and the elution chamber are respectively provided with magnetic bead washing solution and nucleic acid elution solution; a first isolation layer is provided between the magnetic bead adsorption chamber and the washing chamber, and a third isolation layer is provided between the washing chamber and the elution chamber; both the first and third isolation layers are hydrophobic layers; a magnetic rod channel extending between the magnetic bead adsorption chamber, the washing chamber, and the elution chamber is also provided inside the test tube; one end of the magnetic rod channel forms a magnetic rod inlet for the magnetic rod to enter; the device also includes a driving mechanism and a magnetic rod; the magnetic rod can extend into the test tube from the magnetic rod inlet; the magnetic rod includes: a screw and a magnet threadedly connected to the screw; the magnet is used to adsorb magnetic beads; the magnet is circumferentially locked after entering the magnetic rod channel; the driving mechanism is used to drive the screw and the magnet to rotate relative to each other, so that the magnet moves linearly on the screw, moving the magnetic beads from the magnetic bead adsorption chamber to the elution chamber.

[0008] Preferably, the inner wall of the magnetic rod channel is provided with an inwardly protruding rib, which locks the magnet circumferentially; preferably, the rib extends along the entire length of the magnetic rod channel.

[0009] Preferably, the drive mechanism is a motor mounted on the screw, which drives the screw to rotate.

[0010] Preferably, the driving mechanism is a motor connected to the test tube, which drives the test tube to rotate, thereby achieving relative rotation between the magnet and the screw.

[0011] Preferably, the test tube has a locking part on its side wall; preferably, the test tube includes a tube body and a detachable base disposed at the lower end of the tube body; preferably, the locking part is a first locking block that protrudes outward on the side wall of the tube body; preferably, the locking part is a second locking block that protrudes outward on the side wall of the base.

[0012] Preferably, the washing chamber includes a first washing chamber and a second washing chamber, the first washing chamber is located above the second washing chamber, and a second isolation layer is provided between the first washing chamber and the second washing chamber to separate the two; the first washing chamber and the second washing chamber are respectively provided with a first magnetic bead washing liquid and a second magnetic bead washing liquid, and the second isolation layer is a hydrophobic layer.

[0013] Preferably, a first liquid channel is provided on the inner wall of the test tube, and the first liquid outlet of the first liquid channel is located in the first washing chamber. The density of the first isolation layer is less than that of the first magnetic bead washing liquid. The first isolation layer enters the washing chamber through the first liquid channel and floats to the junction of the magnetic bead adsorption chamber and the first washing chamber.

[0014] The inner wall of the test tube is also provided with a second liquid channel, and the second liquid outlet of the second liquid channel is located in the second washing chamber. The density of the second isolation layer is less than that of the second magnetic bead washing liquid. The second isolation layer enters the second washing chamber through the second liquid channel and floats to the junction of the first washing chamber and the second washing chamber.

[0015] Preferably, the test tube is provided with a first separator and a second separator. The first separator corresponds to the position of the first liquid outlet, the first isolation layer is formed inside the first separator, and the top of the first separator is provided with a vent hole. The second separator corresponds to the position of the second liquid outlet, the second isolation layer is formed inside the second separator, and the top of the second separator is provided with a vent hole.

[0016] Preferably, the test tube includes a tube body and a cap disposed on the top of the tube body. The first liquid inlet of the first liquid channel is located at the top of the tube body, and the second liquid inlet of the second liquid channel is located at the top of the tube body. The cap closes the first liquid inlet and the second liquid inlet.

[0017] Preferably, the test tube includes a tube body and a detachable base disposed at the lower end of the tube body. A connecting rod extending longitudinally upward is disposed on the base. The connecting rod is hollow inside and open at the lower end, which is the magnetic rod inlet. The inside of the connecting rod is the magnetic rod channel.

[0018] Preferably, the base is also provided with an upward-facing connection port, which is connected to the inside of the tube body. The second washing chamber is located inside the connection port. The lower part of the base is provided with several independent reaction tubes, and a collection tank is provided inside the reaction tubes. The elution chamber is located inside the collection tank, and the third isolation layer is located at the opening of the collection tank.

[0019] Preferably, the reaction tubes are evenly distributed along the circumference, and the opening of the collection tank is funnel-shaped, wider at the top and narrower at the bottom.

[0020] Preferably, a second partition is provided on the connection port, which covers the upper part of the connection port and leaves a liquid injection port at the second liquid outlet;

[0021] Preferably, a first partition is provided inside the tube body, and the first partition and the second partition are connected to form a second partition plug, and the second isolation layer is formed inside the second partition plug.

[0022] In summary, the beneficial effects of this invention are as follows: The magnetic rod includes a screw and a magnet threaded onto the screw. Through the relative rotation between the magnet and the screw, the magnet moves linearly along the screw, thereby driving the magnetic bead to move within the test tube. Compared to the prior art which involves moving the entire magnetic rod, this shortens the stroke, eliminates the need to move the magnetic rod, and reduces the space required for the device. Furthermore, since the magnet moves along the screw, its position is easily controlled, preventing collisions with the magnetic rod channel. Attached Figure Description

[0023] Figure 1 This is a 3D view of the test tube.

[0024] Figure 2 This is an exploded view of the test tube.

[0025] Figure 3 for Figure 1 Cross-sectional view at point AA.

[0026] Figure 4 for Figure 1 Sectional view at BB

[0027] Figure 5 This is a cross-sectional view of the pipe body.

[0028] Figure 6 This is a three-dimensional view of the first separator.

[0029] Figure 7 This is a 3D view of the base.

[0030] Figure 8 This is a schematic diagram of the interior of the base.

[0031] Figure 9 This is a schematic diagram of the lower part of the base.

[0032] Figure 10 This is a schematic diagram of a test tube and a magnetic rod. Detailed Implementation

[0033] like Figure 1 and 2 As shown, a rapid nucleic acid extraction device is disclosed, particularly suitable for nucleic acid extraction using magnetic beads. The device includes a test tube comprising a tube body 200 and a cap 100 disposed on top of the tube body 200. The cap 100 is typically designed to be detachable or partially openable to facilitate the addition of the sample to be tested and the reagents required for testing into the tube body 200. The tube body 200 includes a main tube and a base 300 disposed at the lower end of the main tube. In this embodiment, the base 300 is detachably disposed on the main tube, and the extracted nucleic acid material is located within the base 300. Therefore, after extraction, the base 300 can be detached from the main tube and taken separately for nucleic acid testing elsewhere.

[0034] like Figure 2 and 3 As shown, the tube body 200 is a hollow tube with an open top. The tube body 200 has a longitudinally extending cavity inside, which is divided from top to bottom into: a magnetic bead adsorption cavity 201, a washing cavity 202, and an elution cavity 203. The washing cavity 202 and elution cavity 203 contain magnetic bead washing solution (not shown) and nucleic acid elution solution (not shown), respectively. It should be noted that the magnetic bead washing solution and nucleic acid elution solution are usually prepared in the test tube when it is assembled; that is, they are prepared in advance before nucleic acid extraction, rather than being added temporarily. The reagents (e.g., nucleic acid lysis buffer, sample, and magnetic beads) in the magnetic bead adsorption chamber 201 can be temporarily added. For example, when the test tube is assembled, lysis buffer (not shown) or a mixture of lysis buffer and magnetic beads can be added to the magnetic bead adsorption chamber 201. Alternatively, lysis buffer or a mixture of lysis buffer and magnetic beads can be temporarily added to the magnetic bead adsorption chamber 201 when nucleic acid extraction is required. Or, when nucleic acid extraction is required, the lysed solution along with the magnetic beads can be directly placed into the magnetic bead adsorption chamber 201. It should also be noted that in this embodiment, the elution chamber 203 is located within the base 300, and the nucleic acid elution buffer and the third isolation layer mentioned below are injected separately after the base 300 is removed from the tube body 200.

[0035] To prevent direct contact between the three liquids in the magnetic bead adsorption chamber 201, washing chamber 202, and elution chamber 203, a first isolation layer 210 is provided between the magnetic bead adsorption chamber 201 and the washing chamber 202, and a third isolation layer (not shown) is provided between the washing chamber 202 and the elution chamber 203. Specifically, the lysis buffer and the magnetic bead washing solution, as well as the magnetic bead washing solution and the nucleic acid elution solution, are separated by the first isolation layer 210 and the third isolation layer, respectively. It should be noted that since the lysis buffer, magnetic bead washing solution, and nucleic acid elution solution are all water-soluble liquids, to ensure effective isolation, both the first isolation layer 210 and the third isolation layer are hydrophobic layers, such as paraffin wax or a hydrophobic liquid layer, specifically one or more of p-bromoanisole, 1-bromo-3-chloropropane, and petrolatum.

[0036] Furthermore, such as Figure 3As shown, to clean impurities from the surface of the magnetic beads, the washing chamber 202 is divided into a first washing chamber 2021 and a second washing chamber 2022. The first washing chamber 2021 is located above the second washing chamber 2022, that is, the first washing chamber 2021 is adjacent to the magnetic bead adsorption chamber 201, and the second washing chamber 2022 is adjacent to the elution chamber 203. The first washing chamber 2021 and the second washing chamber 2022 are separated by a second isolation layer 220. Similar to the first isolation layer 210 and the third isolation layer, the second isolation layer 220 is also a hydrophobic layer, such as paraffin wax or a hydrophobic liquid layer. The first washing chamber 2021 and the second washing chamber 2022 are respectively provided with a first magnetic bead washing solution (not shown) and a second magnetic bead washing solution (not shown). The first magnetic bead washing solution is used to remove impurities such as proteins from the nucleic acids bound to the magnetic beads, and the second magnetic bead washing solution is used to remove impurities such as inorganic salts carried down from the first magnetic bead washing solution.

[0037] like Figure 3 As shown, a magnetic rod channel 230 is provided at the center of the inner cavity of the tube body 200, extending between the magnetic bead adsorption chamber 201, the first washing chamber 2021, and the second washing chamber 2022. The lower end of the magnetic rod channel 230 is located at least at the bottom of the third isolation layer. One end of the magnetic rod channel 230 forms a magnetic rod inlet 231 for a magnetic rod (not shown) to enter. That is, after the magnetic rod extends into the magnetic rod channel 230, it can move between the magnetic bead adsorption chamber 201, the first washing chamber 2021, and the second washing chamber 2022, thereby driving the magnetic bead (not shown) to move accordingly within the test tube, and can move at least to the bottom of the third isolation layer, allowing the magnetic bead to enter the elution chamber 203. Preferably, the lower end of the magnetic rod channel 230 extends to the elution chamber 203, so that the magnetic rod can drive the magnetic bead directly into the nucleic acid elution solution.

[0038] like Figure 10 As shown, the magnetic rod includes a screw 400 and a magnet 500 threaded onto the screw 400. The magnet 500 is used to attract magnetic beads. After entering the magnetic rod channel 230, the magnet 500 is circumferentially locked. Specifically, the inner wall of the magnetic rod channel 230 is provided with an inwardly protruding rib extending along the entire length of the magnetic rod channel 230, which circumferentially locks the magnet 500. A motor is installed on the screw 400, which drives the screw 400 to rotate, thereby causing the magnet 500 to move linearly on the screw 400, moving the magnetic beads from the magnetic bead attraction chamber 201 to the elution chamber 203. Alternatively, the motor can be placed on a test tube, in which case the test tube will drive the magnet 500 to rotate, thus allowing the magnet 500 to also move linearly on the screw 400.

[0039] When performing nucleic acid testing, test tubes typically need to be rotated. To facilitate the rotation of the test tubes by the drive mechanism, the test tubes are equipped with a locking mechanism for easy connection with the drive mechanism. Specifically, for example... Figure 1 and2 As shown, a first engaging block 290 protruding outward is provided on the side wall of the tube body 200. In use, the first engaging block 290 engages in the groove of the drive mechanism, thereby locking the test tube circumferentially so that the drive mechanism can rotate the test tube. In addition, since the base 300 may be removed separately for testing, a second engaging block 360 protruding outward is provided on the side wall of the base, so that when the base 300 is removed, the drive mechanism can rotate the base 300 independently.

[0040] When using the test tube, insert the test tube into the magnetic rod, then place the sample for nucleic acid extraction, a predetermined amount of nano-magnetic beads, and lysis buffer into the magnetic bead adsorption chamber 201. The lysis buffer lyses the extracted material, causing the nucleic acid in the sample to dissolve in the lysis buffer and bind to the magnetic beads. Under the action of magnetic force, the magnetic beads are adsorbed onto the outer wall of the magnetic bead channel 230. After the reaction process is complete, the motor drives the screw 400 to rotate, causing the magnet 500 to move linearly on the screw 400. This causes the magnetic beads to follow the magnet 500 and move synchronously downwards along the outer wall of the magnetic bead channel 230. Thus, the magnetic beads and the nucleic acid on them pass through the first isolation layer 210 and enter the first washing chamber 2021 (if the first isolation layer 210, the second isolation layer 220, and the third isolation layer are made of paraffin, they need to be heated beforehand to melt the paraffin and facilitate the downward movement of the magnetic beads). In the first washing chamber 2021, the first magnetic bead washing solution washes the surface of the magnetic beads, removing impurities such as proteins from the nucleic acids bound to the magnetic beads. Then, the magnetic rod continues to move downwards, and the magnetic beads pass through the second isolation layer 220 into the second washing chamber 2022. In the second washing chamber 2022, the second magnetic bead washing solution washes the surface of the magnetic beads, removing impurities such as inorganic salts carried over from the first magnetic bead washing solution. Afterwards, the magnetic beads continue to move downwards with the magnetic rod, passing through the third isolation layer into the elution chamber 203, where the nucleic acid bound to the magnetic beads is transferred to the nucleic acid elution solution. During detection, PCR or isothermal amplification reactions can be performed directly in the test tube, and molecular beacons can be introduced into the nucleic acid elution solution, allowing external equipment to observe the PCR or isothermal amplification reaction in real time via quantitative fluorescence detection, and to determine the quantity of nucleic acids in the sample by analyzing the fluorescence value; alternatively, the base 300 can be detached from the tube body 200 and taken to other equipment for nucleic acid detection.

[0041] In order to load the first isolation layer 210, the second isolation layer 220, the first magnetic bead washing solution, and the second magnetic bead washing solution into the tube body 200, the inner wall of the tube body 200 is provided with a first liquid channel 240 and a second liquid channel 250. The first liquid channel 240 is used to inject the first magnetic bead washing solution and the first isolation layer 210 into the first washing chamber 2021 in sequence, and the second liquid channel 250 is used to inject the second magnetic bead washing solution and the second isolation layer into the second washing chamber 2022 in sequence.

[0042] Specifically, such as Figure 4 and 5 As shown, the first liquid inlet 241 of the first liquid channel 240 is located at the top of the tube body 200, and the first liquid outlet 242 of the first liquid channel 240 is located inside the first washing chamber 2021. The second liquid inlet 251 of the second liquid channel 250 is located at the top of the tube body 200, and the second liquid outlet 252 of the second liquid channel 250 is located inside the second washing chamber 2022. Therefore, the first liquid outlet 242 is located above the second liquid outlet 252, and is located inside both the first and second washing chambers 2021 and 2022, respectively, allowing the liquid in the corresponding liquid channel to flow into the corresponding location. Furthermore, it should be noted that the density of the first isolation layer 210 is less than that of the first magnetic bead washing liquid, and the density of the second isolation layer 220 is less than that of the second magnetic bead washing liquid. This results in the first isolation layer 210 floating above the first magnetic bead washing liquid and the second isolation layer 220 floating above the second magnetic bead washing liquid during liquid injection.

[0043] In this embodiment, paraffin wax is used as an example to illustrate how these liquids are injected into the tube body 200, with the first isolation layer 210, the second isolation layer 220, and the third isolation layer all being made of this material. First, the base 300 is separated from the main tube. Then, nucleic acid elution solution is injected separately into the base 300, followed by the addition of paraffin wax. After the paraffin wax cools, the third isolation layer described above is formed. The base 300 is then installed at the lower end of the main tube. Next, a predetermined amount of the second magnetic bead washing solution is injected from the second liquid inlet 251, causing the second magnetic bead washing solution to flow out from the second liquid outlet 252. Since a solid third isolation layer has already formed below the second washing chamber 2022, the second magnetic bead washing solution will be held above the third isolation layer. Then, a predetermined amount of liquid paraffin is injected through the second liquid inlet 251, allowing the paraffin to enter the second washing chamber 2022 from the second liquid outlet 252. Note that the density of paraffin is less than that of the second magnetic bead washing liquid, so the paraffin rises to the top of the second magnetic bead washing liquid, forming a second isolation layer 220 above it. The paraffin cools, and the second isolation layer 220 solidifies. Next, a predetermined amount of magnetic bead washing liquid is injected through the first liquid inlet 241, allowing the magnetic bead washing liquid to enter the first washing chamber 2021 from the first liquid outlet 242. Since the paraffin below has solidified, the magnetic bead washing liquid will be held above the second isolation layer 220. Then, a predetermined amount of liquid paraffin is injected through the first liquid inlet 241, allowing it to enter the first washing chamber 2021 from the second liquid outlet 252. Similarly, because the density of paraffin is less than that of the magnetic bead washing liquid, the paraffin floats to the top of the magnetic bead washing liquid, forming a first isolation layer 210 above it. After the paraffin cools, the first isolation layer 210 solidifies. If necessary, the pyrolysis solution can then be injected directly from the opening at the top of the tube body 200.

[0044] The same method applies when a hydrophobic liquid layer is used as the isolation layer. However, it should be noted that the hydrophobic liquid layer will not solidify like paraffin. Therefore, in order to ensure that the third isolation layer can separate the second magnetic bead washing solution and the nucleic acid elution solution, the density of the third isolation layer should be between that of the second magnetic bead washing solution and the nucleic acid elution solution. In order to ensure that the density of the second isolation layer 220 is between that of the first magnetic bead washing solution and the second magnetic bead washing solution, the following applies.

[0045] As can be seen from the above method, the first isolation layer 210 enters the first washing chamber 2021 through the first liquid channel 240 and floats to the junction of the magnetic bead adsorption chamber 201 and the first washing chamber 2021. The second isolation layer 220 enters the second washing chamber 2022 through the second liquid channel 250 and floats to the junction of the first washing chamber 2021 and the second washing chamber 2022.

[0046] The above method eliminates the need for a separator plug to form an isolation layer, as is done in the prior art. The structure of this application simplifies the liquid injection process, which is beneficial for the formation of the first isolation layer 210, the second isolation layer 220, and the third isolation layer. Furthermore, it avoids the problem of the isolation layer failing to provide a sealing function, as is the case in the prior art.

[0047] Furthermore, in this embodiment, the first liquid channel 240 is implemented in the following manner: as follows Figure 5 As shown, a first extension wall 243 is integrally formed on the inner wall of the left side of the tube body 200. The first extension wall 243 is semi-circular, and the two connecting ends 244 of the first extension wall 243 are... Figure 5 This is a cross-sectional view, showing only one connection end 244) is provided on the inner wall of the pipe body 200, and the first extension wall 243 extends inward toward the inner side of the pipe body 200. Figure 5 The first extension wall 243 protrudes from the right side, forming a longitudinally extending first channel between the inner wall of the first extension wall 243 and the inner wall of the tube body 200. The upper end of the first channel is located at the top of the tube body 200, and the lower end of the first channel is located at the first washing chamber 2021. The first channel is the first liquid channel 240.

[0048] In this embodiment, the second liquid channel 250 is implemented in the following manner: Figure 5 As shown, a second extension wall 253 is integrally formed on the inner wall of the right side of the pipe body 200. The second extension wall 253 is semi-circular, and the two connecting ends 254 of the second extension wall 253 are disposed on the inner wall of the pipe body 200, and the second extension wall 253 extends towards the inner side of the pipe body 200. Figure 5The second extension wall 253 protrudes from the left side, forming a longitudinally extending second channel between the inner wall of the second extension wall 253 and the inner wall of the tube body 200. The upper end of the second channel is located at the top of the tube body 200, and the lower end of the second channel is located at the second washing chamber 2022. The second channel is the second liquid channel 250.

[0049] like Figure 5 As shown, the first liquid channel 240 and the second liquid channel 250 are located on opposite sides of the inner wall of the pipe body 200 to avoid stress concentration. At the same time, the large distance between them facilitates the injection of liquid.

[0050] It should be noted that when the materials of the first isolation layer 210 and the second isolation layer 220 are paraffin wax, the tube body 200 can still be fitted with a separator plug as in the prior art, for example in... Figure 3 , 4 In embodiment 5, a first separator 260 and a second separator 270 are provided in the inner cavity of the tube body 200. The first isolation layer 210 is located inside the first separator 260, and the second isolation layer 220 is located inside the second separator 270. However, in this embodiment, the function of the separator is no longer to fill the test tube with paraffin wax, but to facilitate the solidification and shaping of the paraffin wax.

[0051] Figure 5 and Figure 6A schematic diagram of the first separator plug 260 is shown. The shape of the first separator plug 260 is roughly adapted to the inner cavity of the tube body 200. The first separator plug 260 has a first recess 261 and a second recess 262 on its two sides, respectively, adapted to the shapes of the first extension wall 243 and the second extension wall 253. The center of the first separator plug 260 has a central hole 263 adapted to the outer wall of the magnetic rod channel 230. Notably, several ribs 264 are evenly distributed circumferentially on the inner wall of the central hole 263. Typically, the ribs 264 are longitudinally extending strips. Due to the presence of the ribs 264, the first separator plug 260 can fit into the magnetic rod channel 230 without moving freely within the tube body 200. Furthermore, the ribs 264 create a gap between the inner wall of the first separator plug 260 and the outer wall of the magnetic rod channel 230, allowing the magnetic beads to pass through. Furthermore, the first separator plug 260 has a hollow structure with an internal cavity. Several through holes 265 are provided on the peripheral wall of the first separator plug 260, communicating with the internal cavity. The first liquid outlet 242 is located at the through holes 265, allowing paraffin wax to flow out from the first liquid outlet 242 and then enter the cavity through these through holes 265. The first separator plug 260 retains the paraffin wax within the cavity, aiding in its solidification. More importantly, a vent hole 266 is provided on the top surface of the first separator plug 260, allowing internal gas to escape during paraffin wax solidification. This ensures the paraffin wax completely fills the inner cavity of the tube body 200 without gaps. As the paraffin wax gradually cools from the outside in, a dense first isolation layer 210 forms within the tube body 200, ensuring the separation of the liquid below from the liquid above.

[0052] In addition, several upward-protruding stirring rods 267 are provided on the top surface of the first separator 260. The stirring rods 267 are distributed around the circumference. The stirring rods 267 are usually integrally formed on the first separator 260. During the lysis process, shaking or vibrating the test tube will cause the sample and lysis solution to collide with the stirring rods 267, which will play a stirring role and accelerate the reaction process.

[0053] In order to ensure that the first separator plug 260 can be accurately positioned inside the tube body 200, a stepped surface (not shown) is provided on the inner wall of the tube body 200. The lower end of the first separator plug 260 fits on the stepped surface, thereby realizing the positioning of the first separator plug 260.

[0054] like Figure 4 and 5 As shown, the second separator 270 has a shape that is substantially the same as the first separator 260, but more preferably, the second separator 270 includes a first separator 271 and a second separator 272 that are separable from each other. The first separator 271 is integrally formed on the inner wall of the tube body 200, and the second separator 272 is located on the base 300 (see Figure 270). Figure 7The second partition 272 is in the shape of a disc. The second partition 272 serves as the bottom of the second partition plug 270 and can also act as a cover for the base 300 to ensure that the liquid inside the base 300 will not leak out after the base 300 is removed from the tube body 200.

[0055] A cavity is formed between the first partition 271 and the second partition 272, just like the first partition plug 260. The second partition plug 270 also has several through holes in the circumferential direction. The position of the second liquid outlet 252 corresponds to the through hole, so that after the paraffin flows out from the second liquid outlet 252, it flows into the interior of the second partition plug 270. In addition, a gap is left between the second partition plug 270 and the outer wall of the magnetic rod channel 230 for the magnetic bead to pass through. An exhaust hole is also provided on the top surface of the second partition plug 270. The function of the exhaust hole is the same as that in the first partition plug 260.

[0056] like Figure 3 and 4 As shown, in this embodiment, the upper end of the magnetic rod channel 230 is closed, and the magnetic rod inlet 231 is located at the bottom of the base 300. Alternatively, the magnetic rod inlet 231 can be considered to be located at the bottom of the tube body 200 or the test tube.

[0057] As a specific implementation of the magnetic rod channel 230, in this embodiment, such as Figure 7 As shown, a vertically extending, columnar connecting rod 310 is integrally formed on the base 300. The upper end of the connecting rod 310 is closed, the interior is hollow, and the lower end is open. This opening is the magnetic rod inlet 231, and the interior of the connecting rod 310 is the magnetic rod channel 230.

[0058] like Figure 8 As shown, the base 300 is also provided with a connection port 301 that opens upwards. The connection port 301 is connected to the inside of the tube body 200. The second washing chamber 2022 is formed inside the connection port 301. Above the connection port 301 is the second partition 272 mentioned above (see above). Figure 7 The second partition 272 closes the upper part of the connection port 301, but a liquid inlet 302 for liquid to enter is formed at the position of the second liquid channel 250, so that the liquid flowing out from the second liquid outlet 252 can flow into the connection port 301.

[0059] like Figure 7 As shown, in order to install the second partition 272 on the connector 301, the base 300 has upward protruding buckles 320 on opposite sides. The inner side of the buckle 320 is inclined, and a snap-fit ​​groove is formed at the lower end of the buckle 320. The second partition 272 is located in the snap-fit ​​groove, so that the second partition 272 is held on the buckle 320.

[0060] like Figure 9As shown, the lower part of the base 300 is also provided with several independent reaction tubes 330. Typically, there are 4-6 reaction tubes 330. Each reaction tube 330 has a collection trough 303 that opens upwards (see Figure 1). Figure 3 When the nucleic acid eluent is injected, it flows into the collection tank 303 and eventually enters the reaction tube 330. The elution chamber 203 mentioned above is located inside the reaction tube 330. The third isolation layer mentioned above is located at the opening 3031 of the collection tank 303 to encapsulate the eluent inside the reaction tube 330. It is noted that the diameter of the opening 3031 is small; even though the density of paraffin is greater than that of the nucleic acid eluent, the paraffin will remain at the opening 3031 due to surface tension and will not sink below the nucleic acid eluent. The purpose of setting up multiple reaction tubes 330 is to create multiple control groups during nucleic acid detection.

[0061] Furthermore, to facilitate the uniform entry of the magnetic beads into each reaction tube 330 as they move downwards, the reaction tubes 330 are evenly distributed around the circumference, and the slots 3031 are funnel-shaped. Specifically, as shown... Figure 8 As shown, the slot 3031 includes an inclined connecting surface 3032. The tops of the connecting surfaces 3032 of two adjacent slots 3031 intersect to form a connecting line 3033. The connecting line 3033 extends radially, so that each reaction tube 330 has the same area in the circumferential direction. Thus, as the magnetic beads move downward along the outer wall of the magnetic rod channel 230, they will enter each slot 3031 evenly and eventually be evenly distributed in each reaction tube 330.

[0062] To facilitate the installation and fixation of the base 300 and to prevent the base 300 from being installed backwards, a first connecting part is provided on one side of the base 300, and a second connecting part is provided on one side of the tube body 200, with the first connecting part fitting into the second connecting part.

[0063] Specifically, such as Figure 2 As shown, the first connecting part is a groove 340 fixedly installed on the base 300, and the second connecting part is a protrusion 280 provided on the side of the tube body 200 and protruding downward. The protrusion 280 is inserted into the groove 340 and applies force to the position of the groove 340 to fix the base 300 on the tube body 200.

[0064] Furthermore, the base 300 is provided with a radially outward protruding annular flange 350, which abuts against the bottom of the main tube as a limit when connected to the main tube, and a groove 340 is provided on the annular flange 350.

[0065] like Figure 4 As shown, to prevent the liquid in the test tube from leaking out from below, a sealing ring 600 is still provided between the base 300 and the inner wall of the main tube.

[0066] like Figure 4 As shown, the tube cap 100 is disposed on the top of the tube body 200. The tube cap 100 closes the first liquid inlet 241 and the second liquid inlet 251 to prevent the magnetic bead washing liquid from flowing out of the tube body 200.

[0067] Furthermore, the tube cap 100 has a storage section 110, which is cylindrical and extends downward into the tube body 200. A storage opening 111 is formed at the lower end of the storage section 110, and a bottom seal (not shown) is provided at the lower part of the storage opening 111, thereby forming a relatively sealed space in the storage opening 111. Magnetic beads can be placed in this space, so that the magnetic beads are stored in the test tube and no longer need to be carried by an additional container.

[0068] The bottom sealing material can be made of easily tearable or puncturable materials such as tin foil. To facilitate puncturing the tin foil, the tube cap 100 and the tube body 200 can be connected by threads, and the top of the magnetic rod channel 230 is provided with a piercing part 232 facing the bottom sealing and capable of piercing the bottom sealing. In use, the tube cap 100 is screwed downwards, causing the tin foil to move downwards and eventually be punctured by the piercing part 232. Then, the tube cap 100 is screwed in the opposite direction to remove the piercing part 232 from the tin foil, so that the magnetic bead inside the tube cap 100 will fall into the magnetic bead adsorption cavity 201.

[0069] The foregoing description of embodiments of the present invention, through which those skilled in the art are able to implement or use the present invention, will be readily apparent to those skilled in the art. Various modifications to these embodiments will be readily apparent to those skilled in the art. The general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novelty disclosed herein.

Claims

1. A nucleic acid extraction device comprising: The test tube is provided with a magnetic bead adsorption cavity (201), a washing cavity (202) and an elution cavity (203) in sequence, the magnetic bead adsorption cavity (201) and the washing cavity (202) are separated by a first isolation layer (210), the washing cavity (202) and the elution cavity (203) are separated by a third isolation layer, the first isolation layer (210) and the third isolation layer are hydrophobic layers, the test tube is further provided with a magnetic rod channel (230) extending between the magnetic bead adsorption cavity (201), the washing cavity (202) and the elution cavity (203), one end of the magnetic rod channel (230) is formed with a magnetic rod inlet (231) for the magnetic rod to enter the test tube, and the test tube is characterized in that The test tube further comprises a driving mechanism and a magnetic rod, the magnetic rod can extend into the test tube from the magnetic rod inlet (231), the magnetic rod comprises a screw rod (400) and a magnet (500) threadedly connected to the screw rod (400), the magnet (500) is used for adsorbing magnetic beads, the magnet (500) is circumferentially locked after entering the magnetic rod channel (230), and the driving mechanism is used for driving the screw rod (400) to relatively rotate with the magnet (500) so that the magnet (500) moves linearly on the screw rod (400) and moves the magnetic beads from the magnetic bead adsorption cavity (201) to the elution cavity (203).

2. The nucleic acid extraction device according to claim 1, characterized by The inner wall of the magnetic rod channel (230) is provided with a convex strip protruding inward, and the convex strip circumferentially locks the magnet (500).

3. The nucleic acid extraction device according to claim 2, characterized by The convex strip extends along the entire length direction of the magnetic rod channel (230).

4. The nucleic acid extraction device according to claim 1, characterized by, The driving mechanism is a motor arranged on the screw rod (400), and the motor drives the screw rod (400) to rotate.

5. The nucleic acid extraction device according to claim 1, characterized by The driving mechanism is a motor connected to the test tube, and the motor drives the test tube to rotate, so that the magnet (500) relatively rotates with the screw rod (400).

6. The nucleic acid extraction device according to claim 1, wherein The side wall of the test tube is provided with a clamping part.

7. The nucleic acid extraction device according to claim 6, characterized by The test tube comprises a tube body (200) and a base (300) detachably arranged at the lower end of the tube body (200).

8. The nucleic acid extraction device according to claim 7, characterized by The clamping part is a first clamping block (290) protruding outwardly arranged on the side wall of the tube body (200).

9. The nucleic acid extraction device according to claim 7, characterized by The clamping part is a second clamping block (360) protruding outwardly arranged on the side wall of the base (300).

10. The nucleic acid extraction device of claim 1, wherein, The washing cavity (202) comprises a first washing cavity (2021) and a second washing cavity (2022), the first washing cavity (2021) is located above the second washing cavity (2022), and a second isolation layer (220) is arranged between the first washing cavity (2021) and the second washing cavity (2022) to separate the two; the first washing cavity (2021) and the second washing cavity (2022) are respectively provided with first magnetic bead washing liquid and second magnetic bead washing liquid, and the second isolation layer (220) is a hydrophobic layer.

11. The nucleic acid extraction device of claim 10, wherein, The inner wall of the test tube is provided with a first liquid channel (240), and a first liquid outlet (242) of the first liquid channel (240) is located in the first washing cavity (2021); the first isolation layer (210) has a density smaller than that of the first magnetic bead washing liquid, and the first isolation layer (210) enters the washing cavity (202) through the first liquid channel (240) and floats to the junction of the magnetic bead adsorption cavity (201) and the first washing cavity (2021). The inner wall of the test tube is further provided with a second liquid channel (250), and a second liquid outlet (252) of the second liquid channel (250) is located in the second washing cavity (2022); the second isolation layer (220) has a density smaller than that of the second magnetic bead washing liquid, and the second isolation layer (220) enters the second washing cavity (2022) through the second liquid channel (250) and floats to the junction of the first washing cavity (2021) and the second washing cavity (2022).

12. The nucleic acid extraction device of claim 11, wherein, The test tube is provided with a first partition plug (260) and a second partition plug (270); the first partition plug (260) corresponds to the position of the first liquid outlet (242); the first isolation layer (210) is formed inside the first partition plug (260), and the top of the first partition plug (260) is provided with an exhaust hole; the second partition plug (270) corresponds to the position of the second liquid outlet (252); the second isolation layer (220) is formed inside the second partition plug (270), and the top of the second partition plug (270) is provided with an exhaust hole.

13. The nucleic acid extraction device of claim 11, wherein, The test tube comprises a tube body (200) and a tube cover (100) arranged on the top of the tube body (200); a first liquid inlet (241) of the first liquid channel (240) is located on the top of the tube body (200); a second liquid inlet (251) of the second liquid channel (250) is located on the top of the tube body (200); and the tube cover (100) seals the first liquid inlet (241) and the second liquid inlet (251).

14. The nucleic acid extraction device of claim 11, wherein, The test tube comprises a tube body (200) and a base (300) arranged on the lower end of the tube body (200) and separable; the base (300) is provided with a connecting rod (310) extending longitudinally upward; the connecting rod (310) is hollow inside and has an opening at the lower end, which is the magnetic rod inlet (231); and the inside of the connecting rod (310) is the magnetic rod channel (230).

15. The nucleic acid extraction device of claim 14, wherein, The base (300) is further provided with a connecting port (301) opening upward; the connecting port (301) is connected to the inside of the tube body (200); the second washing cavity (2022) is located in the connecting port (301); the lower part of the base (300) is provided with a plurality of independent reaction tubes (330); the reaction tubes (330) are provided with collection grooves (303); the elution cavity (203) is located in the collection grooves (303); and the third isolation layer is located at the groove opening (3031) of the collection groove (303).

16. The nucleic acid extraction device of claim 15, wherein, The reaction tubes (330) are uniformly distributed in the circumferential direction, and the groove opening (3031) of the collection groove (303) has a funnel shape that is large at the top and small at the bottom.

17. The nucleic acid extraction device of claim 15, wherein, The second partition part (272) is arranged on the connecting port (301), and covers the upper part of the connecting port (301) and leaves a liquid injection port (302) at the second liquid outlet (252).

18. The nucleic acid extraction device of claim 15, wherein, The first partition part (271) is further arranged in the pipe body (200), and the first partition part (271) and the second partition part (272) are connected to form a second partition plug (270), and the second partition layer is formed in the second partition plug (270).

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