Automatic liquid suction device and liquid suction method of enzyme-labeled plate washing machine

Abstract

The invention belongs to the field of elisa plate washing equipment, and relates to an automatic liquid suction device and a liquid suction method of an elisa plate washing machine. The automatic liquid suction device comprises a main liquid suction needle, and a main liquid suction cavity and a gravity cavity which are communicated with each other are formed in the main liquid suction needle; the auxiliary liquid suction needle is arranged in the main liquid suction cavity, extends to the lower part of the main liquid suction cavity and is used for sucking residual liquid at the bottom of the plate hole; the driving mechanism is connected with the main liquid suction needle through the buffering piece so that the height of the main liquid suction needle can be changed, and the main liquid suction needle and the auxiliary liquid suction needle suck liquid in sequence. In the liquid suction process of the main liquid suction needle, part of washing liquid in the plate hole of the elisa plate is sucked into the main liquid suction cavity and then enters the gravity cavity, and after the main liquid suction needle and the auxiliary liquid suction needle are pulled to synchronously descend in place, the auxiliary liquid suction needle is close to the bottom of the plate hole to suck residual liquid. According to the invention, the double liquid suction needle modules are adopted and are matched for two times of liquid suction positioning, so that the problems that residual liquid is not thoroughly removed and an elisa plate is easy to damage are solved.

Description

Technical Field

[0001] The present invention belongs to the field of enzyme-labeled plate washing equipment, and particularly relates to an automatic liquid suction device and a liquid suction method for an enzyme-labeled plate washer. Background Art

[0002] An enzyme-labeled plate washer is a key device used in a laboratory to wash enzyme-labeled plates. It completes the washing process by sucking the liquid in the plate wells with a liquid suction needle. In the prior art, the liquid suction needle usually adopts a single-needle structure with a fixed height. During the liquid suction process, when the liquid level drops, it cannot adaptively adjust the liquid suction position, resulting in incomplete removal of the residual liquid at the bottom of the plate well. In addition, some devices use a multi-needle combination for liquid suction, but there are problems such as unreasonable liquid suction sequence, residual liquid still remaining at the bottom of the plate well, and the liquid suction needle touching the bottom and scratching the coating layer at the bottom of the plate well, resulting in incomplete liquid suction and easy damage to the enzyme-labeled plate.

[0003] Therefore, there is an urgent need for an automatic liquid suction device that can suck liquid efficiently and thoroughly in stages and is not easy to damage the enzyme-labeled plate. Summary of the Invention

[0004] The present invention provides an automatic liquid suction device and method for an enzyme-labeled plate washer, aiming to realize the follow-up control of the liquid suction height through the coordinated work of the main liquid suction needle and the auxiliary liquid suction needle, combined with the adaptive adjustment of the gravity chamber and the buffer member, and solve the problems of incomplete removal of residual liquid and easy damage to the enzyme-labeled plate in the prior art.

[0005] The automatic liquid suction device of the enzyme-labeled plate washer includes:

[0006] A main liquid suction needle, which is internally provided with a main liquid suction chamber and a gravity chamber that are interconnected;

[0007] An auxiliary liquid suction needle, which is disposed in the main liquid suction chamber and extends below the main liquid suction chamber for sucking the residual liquid at the bottom of the plate well;

[0008] A driving mechanism, which is connected to the main liquid suction needle through a buffer member to make the height of the main liquid suction needle change with the liquid level, and the main liquid suction needle and the auxiliary liquid suction needle suck liquid in a set sequence;

[0009] Wherein, during the liquid suction process of the main liquid suction needle, part of the washing liquid in the plate well of the enzyme-labeled plate is sucked into the main liquid suction chamber and then enters the gravity chamber, thereby pulling the main liquid suction needle and the auxiliary liquid suction needle to descend synchronously until the main liquid suction needle is blocked by the limit block of the telescopic shaft of the driving mechanism. At this time, the auxiliary liquid suction needle approaches the bottom of the plate well to suck the residual liquid.

[0010] In a preferred embodiment, the main liquid suction chamber and the gravity chamber are separated by a chamber wall, and the chamber wall is provided with a communication hole for the washing liquid to pass through.

[0011] In a preferred embodiment, a sealing assembly is installed at the top of the gravity chamber, and the sealing assembly includes:

[0012] The movable body is installed above the gravity chamber in a vertically sliding manner;

[0013] The sealing plug is fixed to the bottom of the movable body and is sealingly connected to the gravity chamber;

[0014] The elastic member has its upper and lower ends respectively abutted against the top cover of the main liquid suction needle and the movable body;

[0015] The movable body is pulled upward by the liquid suction negative pressure of the auxiliary liquid suction needle to release the sealing connection between the movable body and the gravity chamber.

[0016] In a preferred embodiment, the buffer member of the driving mechanism includes a tension spring and a connecting member mounted on the telescopic shaft of the driving mechanism. The connecting member is used to support the main liquid suction needle. The connecting member is sleeved on the telescopic shaft in a vertically sliding manner and is located above the limiting block;

[0017] The upper end of the tension spring is fixed to the telescopic shaft, and the lower end is fixedly connected to the connecting member. The tension spring is used to apply an upward pulling force to the main liquid suction needle to make the main liquid suction needle descend slowly during the liquid suction process.

[0018] In a preferred embodiment, the auxiliary liquid suction needle is fixed in the main liquid suction cavity through at least two groups of support bodies;

[0019] The liquid inlet at the bottom of the auxiliary liquid suction needle is a bevel. The inner diameter of the needle hole of the auxiliary liquid suction needle is 0.2 - 0.8 mm, and the liquid suction pressure of the auxiliary liquid suction needle is -100 to -70 KPa;

[0020] The liquid suction pressure of the main liquid suction needle is -70 to -40 KPa.

[0021] In a preferred embodiment, the auxiliary liquid suction needle includes an outer needle sleeve and an inner needle that are tightly sleeved. The outer needle sleeve is fixedly connected to the support body. The liquid inlet is provided at the bottom of the inner needle. The inner needle rotates inside the outer needle sleeve when sucking liquid.

[0022] In a preferred embodiment, the driving mechanism is fixed to the bottom plate. A guide needle seat for positioning the inner needle is installed on the lower side of the bottom plate. A guide needle hole matching the outer diameter of the inner needle is arranged in the guide needle seat along the vertical direction.

[0023] In a preferred embodiment, a guiding groove is formed on the outer wall of the inner needle. The guiding groove includes a spiral section and a vertical section that are connected up and down. A ball is installed in the guide needle seat and is embedded in the guiding groove; when the inner needle sucks liquid, the ball slides from the vertical section into the spiral section to guide the rotation of the inner needle.

[0024] In a preferred embodiment, a ring-shaped rubber stopper for closing the main liquid suction chamber is further fixed to the top of the guide needle seat;

[0025] After the main liquid suction needle descends in place, the rubber stopper is embedded in the bottom of the main liquid suction chamber, and the inner and outer sides of the ring structure of the rubber stopper are respectively in close contact with the outer needle and the side wall of the main liquid suction chamber to temporarily close the main liquid suction chamber from below;

[0026] A hydrophobic hole is formed at the bottom of the rubber stopper.

[0027] Another object of the present invention is to provide a liquid suction method for an enzyme-labeled plate washer, including the following steps:

[0028] The liquid suction platform moves above the well of the enzyme-labeled plate; the injection needle injects washing liquid into the well, so that the bottom of the main liquid suction needle is slightly immersed in the washing liquid in the well;

[0029] The driving mechanism receives an extension instruction, controls the telescopic shaft to extend, so that the limit block releases the main liquid suction needle, and the main liquid suction needle gradually descends under the combined action of the tension spring and the gravity chamber;

[0030] While the telescopic shaft extends, the pressure regulating system receives a pressure regulating instruction, controls the suction pump to apply a first negative pressure to the main liquid suction needle, sucks the washing liquid into the main liquid suction needle, and then discharges it from the liquid suction platform; a part of the washing liquid flows into the gravity chamber, and then pulls down the main liquid suction needle, and the main liquid suction needle gradually descends until the main liquid suction needle no longer descends after the auxiliary liquid suction needle approaches the bottom of the well;

[0031] The auxiliary liquid suction needle descends synchronously with the main liquid suction needle. When the auxiliary liquid suction needle is a short distance from the bottom of the well, its inner needle automatically rotates under the action of the guide needle seat, and the pressure regulating system immediately receives a pressure regulating instruction, controls the suction pump to change the pressure, and applies a second negative pressure to the auxiliary liquid suction needle to rotate and suck the residual liquid at the bottom of the well;

[0032] After the residual liquid is sucked up, the pressure regulating system receives a pressure regulating instruction, controls the suction pump to change the pressure, applies a third negative pressure to adsorb the sealing component at the top of the gravity chamber, opens the gravity chamber, and sucks the liquid sucked in the gravity chamber away;

[0033] The pressure regulating system receives a pressure regulating instruction to turn off the suction pump; the driving mechanism receives a retraction instruction, controls the telescopic shaft to retract, and uses the limit block to lift the main liquid suction needle back to the initial position to complete a liquid suction action.

[0034] The beneficial effects of the present invention are:

[0035] The present invention adopts a double liquid suction needle module. The main liquid suction needle has a larger aperture and a faster flow rate, and is responsible for quickly sucking the liquid in the upper and middle parts of the liquid surface; the auxiliary liquid suction needle has a smaller aperture and a higher negative pressure, and can be close to the bottom of the plate hole to suck the residual liquid. With two liquid suction positioning operations for them, mainly the main liquid suction needle sucks the main liquid volume in the upper and middle parts of the liquid surface for the first time, and the auxiliary liquid suction needle sucks the residual liquid near the bottom for the second time, effectively reducing the interfering adsorption at the bottom of the plate hole, reducing the background signal and the difference between holes, and being applicable to enzyme-linked immunosorbent assay (ELISA) plates for high-precision detection, meeting the strict requirements for liquid transfer in, for example, ELISA and polymerase chain reaction (PCR) detections.

[0036] The present invention generates a change in negative pressure through a pressure regulation system to match the liquid suction resistance at different liquid levels. The pressure regulation system applies a higher negative pressure to the auxiliary liquid suction needle, thereby maintaining an effective suction force under low liquid level conditions, forming a local high-pressure area, and effectively peeling off the liquid film attached to the bottom of the hole. This combination of "high resistance - high negative pressure", combined with the specific structures of the main liquid suction needle and the auxiliary liquid suction needle, avoids the problem of insufficient suction force caused by the reduction of the liquid volume.

[0037] The present invention cooperates with a driving mechanism, a buffer, a limit block, a main liquid suction needle, and an auxiliary liquid suction needle to control the main liquid suction needle and the auxiliary liquid suction needle to gradually descend automatically, avoiding the rigid contact of the auxiliary liquid suction needle with the bottom of the plate hole and scratching the coating layer at the bottom of the plate hole, ensuring that the plate hole will not be damaged when sucking the residual liquid. Description of the Drawings

[0038] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation to the present invention. In the drawings:

[0039] Figure 1 is a schematic installation structure diagram of the automatic liquid suction device of the present invention on the support beam of the plate washer;

[0040] Figure 2 is a schematic front view structure diagram of the automatic liquid washing device of the present invention;

[0041] Figure 3 is a schematic structure diagram of the automatic liquid washing device of the present invention hiding the main liquid suction needle and the auxiliary liquid suction needle;

[0042] Figure 4 is a schematic diagram showing the internal structures of the main liquid suction needle and the auxiliary liquid suction needle of the present invention;

[0043] Figure 5 is a schematic bottom view showing the connection structure between the main liquid suction needle and the auxiliary liquid suction needle;

[0044] Figure 6 is a schematic diagram when the main liquid suction needle starts to work;

[0045] Figure 7It is a schematic diagram during the working process of the main liquid suction needle;

[0046] Figure 8 It is a schematic diagram of the auxiliary liquid suction needle rotating to wash the liquid;

[0047] Figure 9 It is Figure 8 The enlarged schematic diagram of the structure at position A in

[0048] Figure 10 It is a top view structural schematic diagram of the movable body and the elastic member of the sealing assembly;

[0049] Figure 11 It is a structural schematic diagram of the sealing assembly of the present invention.

[0050] The markings in the figure are:

[0051] 1. Liquid suction platform; 11. Liquid suction flow channel; 12. Guide rail;

[0052] 2. Main liquid suction needle; 21. Main liquid suction cavity; 22. Gravity cavity; 23. Cavity wall; 231. Communication hole; 24. Sealing assembly; 241. Movable body; 242. Elastic member; 243. Sealing plug; 25. Top cover; 26. Needle fixing sleeve; 27. Support body;

[0053] 3. Auxiliary liquid suction needle; 31. Outer needle sleeve; 32. Inner needle; 321. Guide groove; 3211. Spiral section; 3212. Vertical section;

[0054] 4. Driving mechanism; 41. Limit block; 42. Telescopic shaft; 43. Tensile spring; 44. Connecting member;

[0055] 5. Bottom plate; 51. Slide rail;

[0056] 6. Needle guide seat; 61. Needle guide hole; 62. Ball; 63. Rubber plug; 64. Hydrophobic hole;

[0057] 7. Support beam; 8. Z-axis module; 9. Plate hole. Specific embodiments

[0058] As Figure 1 shown, a Z-axis module 8 is installed on the support beam 7 of the microplate washer, and a liquid injection platform (not shown) and a liquid suction platform 1 are installed at the output end of the Z-axis module 8. The support beam 7 can drive the liquid injection platform and the liquid suction platform 1 to translate above each row of plate holes 9 to sequentially wash the plate holes 9 of the microplate. For the convenience of display, only one plate hole is drawn in the attached Figures 6 - 8 figures, and the structures of other plate holes are similar to it. The Z-axis module 8 can drive the liquid injection platform and the liquid suction platform 1 to lift to the set height respectively, which is convenient for liquid injection and liquid suction.

[0059] The automatic liquid suction device is installed below the liquid suction platform 1, and the liquid suction platform 1 is connected to a suction pump and a waste liquid collection container. The pressure regulation system of the plate washer controls the operation of the air extraction pump to suck the liquid in the plate holes.

[0060] Please refer to Figures 2 - 4 , the automatic liquid suction device includes a main liquid suction needle 2, an auxiliary liquid suction needle 3, a driving mechanism 4 and a bottom plate 5. The upper end of the driving mechanism 4 is fixed to the output end of the Z-axis module 8 by fasteners such as screws, and the lower side of the driving mechanism 4 is fixedly installed on the vertical bottom plate 5.

[0061] Both the main liquid suction needle 2 and the auxiliary liquid suction needle 3 are installed on the bottom plate 5, and liquid is sucked in sequence, that is, two liquid suction positionings are performed: for the first time, mainly the main liquid suction needle 2 sucks the main liquid volume in the upper and middle parts of the liquid surface, and the auxiliary liquid suction needle 3 cooperates to suck the liquid; for the second time, the auxiliary liquid suction needle 3 sucks the residual liquid near the bottom of the plate hole.

[0062] The main liquid suction needle 2 is driven by the driving mechanism 4 to be installed on the bottom plate 5 in a sliding up and down manner, and a main liquid suction cavity 21 and a gravity cavity 22 that communicate with each other are arranged inside it. When the main liquid suction needle 2 sucks liquid, most of the washing liquid in the plate hole 9 of the ELISA plate is sucked into the main liquid suction cavity 21 and then drained away, and a part of the washing liquid seeps into the gravity cavity 22, thereby pulling the main liquid suction needle 2 and the auxiliary liquid suction needle 3 to descend synchronously.

[0063] The auxiliary liquid suction needle 3 is arranged in the main liquid suction cavity 21 and extends below the main liquid suction cavity 21. When the main liquid suction needle 2 stops sucking liquid, the auxiliary liquid suction needle 3 is enabled to suck the residual liquid at the bottom of the plate hole.

[0064] In a specific embodiment, the liquid suction pressure of the main liquid suction needle 2, that is, the first negative pressure, is -70 to -40 KPa, and the liquid suction pressure of the auxiliary liquid suction needle 3, that is, the second negative pressure, is -100 to -70 KPa. A greater liquid suction negative pressure is applied inside the auxiliary liquid suction needle 3 to match the greater liquid suction resistance of the residual liquid at the bottom of the plate hole, and the residual liquid can be effectively sucked.

[0065] A limit block 41 is installed at the end of the telescopic shaft 42 of the driving mechanism 4. The limit block 41 protrudes outward relative to the telescopic shaft 42. When the washing liquid in the gravity cavity 22 pulls the main liquid suction needle 2 to descend to a set height, the limit block 41 restricts the moving stroke of the main liquid suction needle 2 and makes it stop descending.

[0066] A buffer member is also slidably installed on the telescopic shaft 42. The driving mechanism 4 is connected to the main liquid suction needle 2 through the buffer member. Thus, when the telescopic shaft 42 of the driving mechanism 4 extends in place, the buffer member can control the main liquid suction cavity 21 to gradually descend instead of suddenly descending to the bottom, avoiding the rigid collision of the auxiliary liquid suction needle 3 located below the main liquid suction needle 2 with the bottom of the plate hole and scratching the coating layer at the bottom of the plate hole to damage the plate hole 9.

[0067] Specifically, please refer toFigures 6 to 8 , the buffer member includes a connecting member 44 sleeved on the telescopic shaft 42 and a tension spring 43. The connecting member 44 is located above the limit block 41 and is fixedly connected to the main liquid suction needle 2 to support the main liquid suction needle 2. The connecting member 44 can slide up and down along the telescopic shaft 42. An optional shape of the connecting member is L-shaped. A limit ring is fixedly installed on the telescopic shaft 42. The upper end of the tension spring 43 is fixed to the limit ring and the lower end is fixedly connected to the connecting member 44. The pulling force exerted by the tension spring 43 on the main liquid suction needle does not need to be too large, just enough to enable the main liquid suction needle to gradually descend. When the telescopic shaft 42 of the driving mechanism 4 contracts, the tension spring 43 is also in a contracted state; when the telescopic shaft 42 extends, the tension spring 43 exerts an upward pulling force on the main liquid suction needle 2 through the connecting member 44, so that the main liquid suction needle 2 is temporarily maintained near the original height at the start of liquid suction, and then slowly descends during the liquid suction process.

[0068] The specific structure of the main liquid suction needle 2 is introduced below. The main liquid suction cavity 21 of the main liquid suction needle 2 is preferably arranged on the central axis of the main liquid suction needle 2. It is a structure that penetrates up and down, and the cavity diameter is relatively large to facilitate the rapid passage of the cleaning liquid. As Figure 4 and Figure 5 shown, support bodies 27 are arranged at the upper and lower ends of the main liquid suction cavity 21 to fixedly connect the auxiliary liquid suction needles 3. The support bodies 27 are rod-shaped members, and a plurality of support bodies 27 are radially distributed to ensure that the auxiliary liquid suction needles 3 are fixedly connected to the main liquid suction cavity 21 in a balanced and reliable manner. A gravity cavity 22 is provided outside the main liquid suction cavity 21. The main liquid suction cavity and the gravity cavity are separated by a cavity wall 23. Optionally, the gravity cavity 22 is coaxially arranged with the main liquid suction cavity 21. A communication hole 231 for the cleaning liquid to pass through is opened on the cavity wall 23.

[0069] Please refer to Figure 4 , Figures 6 to 10 , a top cover 25 is installed at the top of the main liquid suction needle 2. A cover hole for the cleaning liquid to flow out is provided in the center of the top cover 25. The top cover 25 is located above the gravity cavity 22. The top of the gravity cavity 22 is open, and a sealing assembly 24 is installed at the opening. The sealing assembly 24 temporarily blocks the cleaning liquid from flowing out of the gravity cavity 22 when the main liquid suction needle 2 is working. The sealing assembly 24 includes a movable body 41 and elastic members 242 and a sealing plug 243 located on the upper and lower sides of the movable body 41 respectively. The upper and lower ends of the elastic member 242 are respectively abutted against the top cover 25 and the movable body 41. The elastic member 242 is an elastic element such as a compression spring or a spring sheet that can be repeatedly squeezed and deformed. The movable body 41 is closely attached to the inner wall of the main liquid suction needle, and the movable body can be selected as an annular sheet structure. The sealing plug 243 is also annular and is adapted to the opening width at the top of the gravity cavity 22. The sealing plug 243 seals the opening under the thrust of the elastic member 242.

[0070] When the auxiliary liquid-absorbing needle 3 completes the liquid-absorbing, the liquid-absorbing negative pressure of the suction pump further increases to the third pressure, which is sufficient to absorb the movable body 41 upward, so that the movable body 41 squeezes the elastic member 242, and then the sealing plug 243 is separated from the opening of the gravity chamber 22, and the sealing connection between the movable body 41 and the gravity chamber 22 is released, and then the washing liquid in the gravity chamber 22 is sucked away through the opening and the connecting hole 231, and the gravity of the main liquid-absorbing needle gradually decreases. Subsequently, the driving mechanism 4 resets the telescopic shaft 42 upward, and the limit block 41 pulls the connecting member 44 and the main liquid-absorbing needle 2 to the initial height.

[0071] A needle fixing sleeve 26 is fixed to the outside of the main pipetting needle 2, and the needle fixing sleeve 26 is fixedly connected to the connecting piece 44 by screws.

[0072] In order to ensure that the main pipetting needle 2 can move up and down stably, a slide rail 51 is also installed on the bottom plate 5. A slide groove matching the slide rail 51 is arranged on the back of the main pipetting needle 2, and the main pipetting needle 2 moves up and down along the slide rail 51.

[0073] The specific structure of the auxiliary liquid-imbibing needle 3 is introduced below. As mentioned above, the auxiliary liquid-imbibing needle 3 is fixed in the main liquid-imbibing cavity 21 by the support body 27. The liquid inlet at the bottom of the auxiliary liquid-imbibing needle 3 is a slope, and the sloped liquid inlet can quickly absorb the washing liquid and reduce liquid residue; the slope shape can also use geometric mutations to produce pressure changes when the fluid passes through, thereby promoting the self-transport of the fluid along the channel. The inner diameter of the needle hole of the auxiliary liquid-imbibing needle 3 is 0.2-0.8mm, preferably 0.4-0.7mm. Compared with the main liquid-imbibing cavity, the smaller aperture of the auxiliary liquid-imbibing needle can enhance the capillary action and use the capillary suction force to improve the liquid-imbibing capacity; in addition, it can also accurately match the volume of the residual liquid (usually <5μL) to avoid suction dispersion or liquid back-infiltration due to excessive aperture.

[0074] Since the auxiliary pipetting needle 3 is fixedly connected to the main pipetting needle 2, and the main pipetting needle 2 is connected to the tension spring 43, when the auxiliary pipetting needle 3 accidentally touches the bottom of the plate hole, it moves upward under the buffering action of the tension spring 43, thereby immediately stopping the descending action to prevent damage to the plate hole structure due to excessive contact.

[0075] Example 2

[0076] like Figure 4 , Figures 6 to 8 as well as Figure 11 As shown, based on Example 1, this embodiment installs a guide needle seat 6 for positioning the inner needle 32 on the lower side of the base plate 5, and a guide needle hole 61 matching the outer diameter of the inner needle 32 is arranged in the guide needle seat 6 along the vertical direction. The guide needle seat 6 guides the inner needle 32 to move vertically downward to prevent the inner needle 32 from shaking, thereby improving the stability of liquid aspiration.

[0077] The auxiliary liquid suction needle 3 includes an outer needle sleeve 31 and an inner needle 32 that are tightly sleeved. A rotational connection can be achieved between the outer needle sleeve 31 and the inner needle 32 through a conventional bearing, and the inner needle is restricted from moving up and down relative to the outer needle sleeve. The outer needle sleeve 31 is fixedly connected to the support body 27. The inner needle 32 is used to suck up residual liquid. When sucking liquid, the inner needle 32 rotates inside the outer needle sleeve 31 to achieve omnidirectional liquid suction and reduce dead corners of liquid retention. In a specific test, the auxiliary liquid suction needle can reduce the residual amount in the plate hole from >5 μL to <1 μL.

[0078] The rotation of the inner needle 32 is achieved through the following structure: a guiding groove 321 is formed on the outer wall of the inner needle 32. The guiding groove 321 includes a spiral section 3211 and a vertical section 3212 that are connected up and down. A ball groove is provided on the side wall of the needle guiding hole 61, and a ball 62 is embedded in the ball groove. The part of the ball 62 protruding out of the ball groove is embedded in the guiding groove 321. As Figure 11 shown, when the inner needle 32 moves downward to suck liquid, the ball 62 slides from the vertical section 3212 into the spiral section 3211, thereby guiding the inner needle 32 to automatically rotate.

[0079] In a preferred embodiment, a rubber plug 63 for closing the main liquid suction cavity 21 is further fixed to the top of the needle guiding seat 6. The rubber plug 63 is annular. When the main liquid suction needle 2 descends to a specified position, the rubber plug 63 is embedded in the bottom of the main liquid suction cavity 21, and the inner and outer sides of its annular structure are respectively close to the outer needle and the side wall of the main liquid suction cavity 21, thereby temporarily closing the main liquid suction cavity 21 from below. Subsequently, a relatively large second negative pressure is applied to the auxiliary liquid suction needle 3 by the suction pump. Since the bottom of the main liquid suction cavity 21 has been blocked by the rubber plug 63, the liquid suction flow path can only communicate with the atmosphere through the liquid inlet of the auxiliary liquid suction needle 3. In this way, the pressure loss caused by the opening at the bottom of the main liquid suction cavity is avoided, ensuring that the auxiliary liquid suction needle 3 can suck liquid stably.

[0080] In a preferred embodiment, a number of hydrophobic holes 64 are arrayed at the bottom of the rubber plug 63. When the main liquid suction needle 2 is working, these hydrophobic holes 64 allow the liquid sucked inside the rubber plug 63 to flow out smoothly, thereby avoiding the retention of washing liquid in the rubber plug 63 and improving the cleaning effect on the plate hole.

[0081] The surfaces of the bottom plate, the main liquid suction needle, the auxiliary liquid suction needle, the telescopic shaft, the limit block, and the needle guiding seat in this embodiment are all sprayed with a hydrophobic layer to reduce the possibility of liquid droplets adhering.

[0082] Embodiment 3

[0083] Figure 1 The schematic diagram of the installation structure of the automatic liquid suction device on the support beam of the microplate washer is disclosed. Some parts are omitted in the figure, and only a schematic diagram of the principle is shown. Please refer to Figure 1, the automatic liquid suction device of this embodiment is installed on the liquid suction platform 1. A row of main liquid suction needles 2 is installed on the liquid suction platform 1, and at least one of the main liquid suction needles 2 is driven by a driving mechanism 4 to move up and down. Therefore, the liquid suction platform 1 and the other main liquid suction needles 2 also move up and down synchronously, so as to reduce the number of driving mechanisms 4 and simplify the device structure. However, stretching springs 43 and connecting pieces 44 need to be configured for the other main liquid suction needles 2 to ensure that each main liquid suction needle 2 descends synchronously.

[0084] In order to enable the liquid suction platform 1 to lift and lower stably, guide rails 12 are installed on the left and right sides of the liquid suction platform 1. Correspondingly, guide grooves are provided on the left and right sides of the support beam 7 of the plate washer to guide the liquid suction platform 1 to slide smoothly in the vertical direction.

[0085] A liquid suction flow channel 11 is arranged inside the liquid suction platform 1. Each main liquid suction needle 2 and auxiliary liquid suction needle 3 are communicated with the liquid suction flow channel 11, and the liquid suction flow channel 11 is connected to a waste liquid collection container through a suction pump. When the suction pump is started, the washing liquid in the plate holes will be pumped into the waste liquid collection container through the liquid suction flow channel 11.

[0086] The following combines Figures 6 - 8 to illustrate the liquid suction method of the above enzyme-labeled plate washer automatic liquid suction device, including the following steps:

[0087] The plate washer sends a movement instruction to move the liquid suction platform 1 above the plate hole 9 of the enzyme-labeled plate;

[0088] The plate washer sends a liquid injection instruction to control the liquid injection needle to inject washing liquid into the plate hole 9, and the bottom of the main liquid suction needle 2 is immersed in the washing liquid in the plate hole;

[0089] The driving mechanism 4 receives an extension instruction to control the telescopic shaft 42 to extend, so that the limiting block 41 releases the pressure on the connecting piece 44, and then releases the main liquid suction needle 2. The main liquid suction needle 2 gradually descends under the combined action of the stretching spring 43 and the gravity chamber 22;

[0090] While the telescopic shaft 42 extends, the pressure regulating system receives a pressure regulating instruction to control the suction pump to apply a first negative pressure to the main liquid suction needle 2, suck the washing liquid into the main liquid suction needle 2, and then discharge it from the liquid suction platform 1; a part of the washing liquid seeps into the gravity chamber 22, and then uses the increased gravity to pull down the main liquid suction needle 2. The main liquid suction needle 2 gradually overcomes the pulling force of the stretching spring 43 and descends, which is convenient for more efficient liquid suction until the main liquid suction needle 2 no longer descends after the auxiliary liquid suction needle 3 approaches the bottom of the plate hole;

[0091] While the main liquid suction needle 2 descends, the auxiliary liquid suction needle 3 also descends synchronously. Since the bottom of the auxiliary liquid suction needle is also connected to the washing liquid in the plate hole, when the main liquid suction needle sucks the liquid, the auxiliary liquid suction needle also sucks the liquid as an auxiliary with the same pressure. Therefore, the washing liquid can be sucked away more quickly. When the auxiliary liquid suction needle 3 is at a short distance from the bottom of the plate hole, its inner needle 32 automatically rotates under the action of the balls in the needle guide seat. The pressure regulating system then receives the pressure regulating instruction, controls the suction pump to change the pressure, and applies a second negative pressure to the auxiliary liquid suction needle 3. The inner needle 32 of the auxiliary liquid suction needle 3 simultaneously descends, rotates, and sucks the liquid to ensure that it can completely remove the residual washing liquid in all directions at the bottom of the plate hole; at this time, the bottom of the main liquid suction cavity 21 is sealed by the rubber plug 63, so the main liquid suction needle does not work;

[0092] After the residual liquid is sucked up, the pressure regulating system receives the pressure regulating instruction, controls the suction pump to change the pressure, and applies a third negative pressure to adsorb the sealing component 24 at the top of the gravity cavity 22, opens the gravity cavity 22, and sucks away the liquid sucked in the gravity cavity 22;

[0093] Subsequently, the pressure regulating system receives the pressure regulating instruction to turn off the suction pump, and the sealing component 24 resets under the action of the elastic member; the driving mechanism 4 receives the retraction instruction, controls the telescopic shaft 42 to retract, and uses the limit block 41 to raise the main liquid suction needle 2 to the initial position, completing a liquid suction operation. The above process is continuously repeated.

[0094] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An automatic liquid aspiration device for an enzyme-labeled plate washer, characterized in that: include: The main liquid aspiration needle has a main liquid aspiration cavity and a gravity cavity interconnected therein; An auxiliary liquid aspiration needle is disposed in the main liquid aspiration cavity and extends to the bottom of the main liquid aspiration cavity, and is used to aspirate the residual liquid at the bottom of the plate well of the ELISA plate; A driving mechanism is connected to the main liquid aspiration needle through a buffer so that the height of the main liquid aspiration needle changes to aspirate the main liquid volume in the upper part of the liquid surface in the plate hole; Among them, during the liquid aspiration process of the main liquid aspiration needle, part of the washing liquid is sucked into the main liquid aspiration chamber and then enters the gravity chamber, thereby pulling the main liquid aspiration needle and the auxiliary liquid aspiration needle down synchronously until the main liquid aspiration needle is blocked by the limit block of the telescopic shaft of the driving mechanism. At this time, the auxiliary liquid aspiration needle approaches the bottom of the plate hole to aspirate the residual liquid.

2. The automatic liquid suction device according to claim 1, characterized in that: The main liquid suction cavity and the gravity cavity are separated by a cavity wall, and the cavity wall is provided with a connecting hole for the washing liquid to pass through.

3. The automatic liquid suction device according to claim 2, characterized in that: A sealing assembly is installed at the top of the gravity chamber, and the sealing assembly includes: A movable body is installed above the gravity chamber in an up-and-down sliding manner; A sealing plug, fixed to the bottom of the movable body and sealingly connected to the gravity chamber; An elastic member, the upper and lower ends of which respectively abut against the top cover of the main liquid-pipetting needle and the movable body; The negative pressure of the auxiliary liquid-pipetting needle is used to pull the movable body upward to release the sealed connection between the movable body and the gravity chamber.

4. The automatic liquid suction device according to claim 2, characterized in that: The buffer of the driving mechanism comprises a tension spring and a connecting member installed on the telescopic shaft of the driving mechanism, the connecting member is used to support the main liquid aspiration needle, the connecting member is slidably sleeved on the telescopic shaft up and down, and is located above the limit block; The upper end of the stretch spring is fixed on the telescopic shaft, and the lower end is fixedly connected to the connecting piece. The stretch spring is used to apply an upward pulling force to the main liquid aspiration needle so that the main liquid aspiration needle descends slowly during the liquid aspiration process.

5. The automatic liquid suction device according to claim 4, characterized in that: The auxiliary liquid-sucking needle is fixed in the main liquid-sucking cavity by at least two sets of supporting bodies; The liquid inlet at the bottom of the auxiliary liquid-pipetting needle is an inclined surface, the inner diameter of the needle hole of the auxiliary liquid-pipetting needle is 0.2-0.8 mm, and the liquid-pipetting pressure of the auxiliary liquid-pipetting needle is -100 to -70 KPa; The liquid aspiration pressure of the main liquid aspiration needle is -70 to -40 KPa.

6. The automatic liquid suction device according to claim 5, characterized in that: The auxiliary liquid-absorbing needle comprises an outer needle sleeve and an inner needle which are tightly sleeved together. The outer needle sleeve is fixedly connected to the support body. The liquid inlet is arranged at the bottom of the inner needle. When the inner needle absorbs liquid, it rotates inside the outer needle sleeve.

7. The automatic liquid suction device according to claim 6, characterized in that: The driving mechanism is fixed on the bottom plate, a guide needle seat for positioning the inner needle is installed on the lower side of the bottom plate, and a guide needle hole matching the outer diameter of the inner needle is arranged in the guide needle seat along the vertical direction.

8. The automatic liquid suction device according to claim 7, characterized in that: The outer wall of the inner needle is formed with a guide groove, which includes a spiral section and a vertical section connected up and down. A ball embedded in the guide groove is installed in the guide needle seat; when the inner needle absorbs liquid, the ball slides from the vertical section into the spiral section to guide the inner needle to rotate.

9. The automatic liquid suction device according to claim 7, characterized in that: A ring-shaped rubber plug for closing the main liquid aspiration cavity is also fixed on the top of the guide needle seat; When the main aspiration needle is lowered into place, the rubber plug is embedded in the bottom of the main aspiration cavity, and the inner and outer sides of the annular structure of the rubber plug are respectively in close contact with the outer needle sleeve and the side wall of the main aspiration cavity, so as to temporarily close the main aspiration cavity from below; The bottom of the rubber plug is formed with a hydrophobic hole.

10. A liquid aspiration method for an enzyme-labeled plate washer, implemented by the automatic liquid aspiration device according to any one of claims 1 to 9, characterized in that: The following steps are involved: The main aspiration needle is immersed in the washing solution in the plate hole; The driving mechanism receives the extension instruction and controls the telescopic shaft to extend, so that the limit block releases the main liquid-absorbing needle, and the main liquid-absorbing needle gradually descends under the joint action of the buffer member; When the telescopic shaft is extended, the pressure regulating system receives the pressure regulating instruction, controls the suction pump to apply a first negative pressure to the main liquid aspiration needle, and sucks the washing liquid into the main liquid aspiration needle, and then discharges the liquid aspiration platform; a part of the washing liquid flows into the gravity chamber, and then pulls the main liquid aspiration needle downward, and the main liquid aspiration needle gradually descends until the auxiliary liquid aspiration needle approaches the bottom of the plate hole and the main liquid aspiration needle no longer descends; The auxiliary liquid-absorbing needle follows the main liquid-absorbing needle and descends synchronously. When the auxiliary liquid-absorbing needle is a short distance away from the bottom of the plate hole, the inner needle thereof automatically rotates under the action of the needle guide seat. The pressure regulating system then receives the pressure regulating instruction, controls the suction pump to change the pressure, and applies a second negative pressure to the auxiliary liquid-absorbing needle, so that the auxiliary liquid-absorbing needle rotates to absorb the residual liquid at the bottom of the plate hole. After the residual liquid is sucked out, the pressure regulating system receives the pressure regulating instruction, controls the suction pump to change the pressure, applies the third negative pressure to adsorb the sealing component at the top of the gravity chamber, opens the gravity chamber, and sucks away the suction liquid in the gravity chamber; The pressure regulating system receives the pressure regulating instruction and shuts down the suction pump; The driving mechanism receives the retraction instruction, controls the telescopic shaft to retract, and uses the limit block to raise the main liquid aspiration needle back to the initial position to complete a liquid aspiration action.

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