A suction filtration device for CTC enrichment and staining

Abstract

The present invention relates to the technical field of medical testing equipment, specifically a suction filtration device for CTC enrichment and staining, comprising a fixed assembly and a microfluidic chip mounted on the fixed assembly. The microfluidic chip includes a reagent tank and a rigid chip fixing plate disposed at the lower end of the reagent tank. The rigid chip fixing plate is provided with a through hole 1, within which the chip body is placed. The reagent tank is a sheet-like structure with a liquid leakage hole extending longitudinally through the body. The lower surface of the rigid chip fixing plate is provided with a liquid suction assembly. The suction filtration device utilizes a rigid chip with uniform pore size and low filtrate residue, effectively preventing cell stacking or compaction caused by excessive negative pressure during suction filtration, thereby improving the quality of cell enrichment and staining. The fixed assembly can remove residual reagents from the chip by swinging and tilting the fixed assembly, facilitating automated operation.

Description

Technical Field

[0001] The present invention relates to the technical field of medical testing equipment, in particular to a suction filtration device for CTC enrichment and staining. Background Art

[0002] Circulating tumor cell (CTC) detection is an emerging tumor diagnostic technology that has emerged in recent years. Research indicates that circulating tumor cells can be detected in peripheral blood before solid tumors develop, making CTC detection highly suitable for early screening and diagnosis of malignant tumors. CTC detection is also highly effective in prognosis, disease progression monitoring, recurrence prediction, monitoring of microscopic lesions after surgery, and designing and monitoring the efficacy of targeted drug therapy. It is currently an advanced method for early screening and diagnosis of malignant tumors. However, due to the low levels of circulating tumor cells in peripheral blood, capturing and identifying them in CTC detection presents significant challenges. Microfluidic chips, also known as microporous membranes, are key components for enriching circulating tumor cells. Existing microporous membranes all use flexible fiber membranes or filter paper as filter media. For example, another Chinese patent application filed by the applicant, entitled "A Microfluidic Device and Integrated Cell Enrichment and Staining Apparatus," has the authorization publication number CN220371064U. The microfluidic device comprises an effusion lining, a filter assembly, and a lining mesh. The interior of the effusion liner is a funnel-shaped structure, provided with a guide strip protruding from the surface of the funnel-shaped structure for guiding the filtrate; the filter assembly is a microfiltration membrane provided above the effusion liner for filtering liquid samples. The pore size of the microfiltration membrane made of flexible material is uneven, the capillary phenomenon is more obvious and wrinkles are easily formed, and the filtrate is easily retained in the filter membrane. Therefore, it is necessary to set auxiliary devices such as a negative pressure pump and a water absorption layer below to absorb excess filtrate from the microfiltration membrane. If the negative pressure is too large, it is easy to cause cell stacking or compaction. The use of a rigid membrane can effectively avoid wrinkles, and no bubbles will appear during the enrichment and staining process, which will not affect subsequent microscopic observation. However, due to the lack of negative pressure suction filtration, this rigid microfluidic chip can only remove residual reagents in the chip by swinging or tilting. The fixing devices of existing microfluidic chips cannot achieve swinging and tilting movements. Summary of the Invention

[0003] In order to solve the above-mentioned problems of the prior art, the present invention provides a swingable and tiltable suction filter device for CTC enrichment and staining, including a fixed component, to avoid the generation of wrinkles and bubbles, and to remove residual reagents in the chip by swinging and tilting.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] The present invention discloses a suction filtration device for CTC enrichment and staining, comprising a fixing assembly and a microfluidic chip mounted on the fixing assembly. The microfluidic chip comprises a reagent tank and a rigid chip fixing plate disposed at the lower end of the reagent tank. The rigid chip fixing plate is provided with a through hole 1, in which the chip body is placed. The reagent tank is a sheet-like structure with a liquid leakage hole extending longitudinally through the body. The lower surface of the rigid chip fixing plate is provided with a liquid suction assembly.

[0006] Preferably, the fixing assembly includes an upper frame and a lower frame arranged parallel to each other, a left frame and a right frame parallel to each other are fixedly connected between the upper frame and the lower frame, rollers are installed at both ends of the upper frame and the lower frame, and upper guide plates and lower guide plates arranged opposite to each other are fixedly connected on the side walls of the upper frame and the lower frame, and the upper guide plates and the lower guide plates are both strip structures with L-shaped cross-sections; the left frame and the right frame are provided with upper guide holes at positions corresponding to the upper guide plates, and lower guide holes at positions corresponding to the lower guide plates; the two ends of the rigid chip fixing plate are overlapped on the upper guide plates and the lower guide plates.

[0007] With the above structural design, the rigid chip is installed between the upper frame and the lower frame. The residual reagents in the reagent tank and the chip can be removed by swinging and tilting the fixed assembly, which facilitates automated operation.

[0008] Preferably, the chip body is made of a transparent rigid material, and a plurality of groups of long strip-shaped micropores are evenly distributed on the chip body; the micropores on the chip body include transverse holes arranged transversely and vertical holes arranged longitudinally.

[0009] With the above structural design, the rigid chip body can avoid wrinkles and bubbles during the enrichment and staining process.

[0010] Preferably, the liquid absorption component includes filter paper adhered to the lower surface of the rigid chip fixing plate, and a polymer water-absorbing material layer provided between the filter paper and the rigid chip fixing plate.

[0011] This structural design utilizes polymer absorbent materials to fully absorb various reagents, replacing conventional filtration components, reducing equipment size and costs. It effectively prevents cell stacking or compaction caused by excessive negative pressure during filtration.

[0012] Preferably, the polymer water-absorbing material layer of the liquid-absorbing component covers the entire first through hole, and a gasket is provided between the lower surface of the rigid chip fixing plate and the liquid-absorbing component, and the gasket surrounds the polymer water-absorbing material layer.

[0013] With the above structural design, the gasket fixes the powdered polymer material within the range of the gasket, preventing the powdered polymer material from being excessively dispersed and affecting the water absorption effect.

[0014] Preferably, a suction filter chamber is detachably mounted on the lower end of the reagent tank through a first card slot. The suction filter chamber is a container with an upper end open and receiving the leakage hole. The rigid chip fixing plate is located between the reagent tank and the suction filter chamber.

[0015] With the above structural design, the suction filter bin can conveniently collect waste reagents and suction components that pass through the leakage hole.

[0016] Preferably, a funnel-shaped liquid collecting groove is provided on the upper surface of the reagent tank, and the lower end of the liquid collecting groove is connected to the liquid leakage hole.

[0017] With the above structural design, a liquid collecting tank is provided to facilitate the temporary storage of blood and various reagents added subsequently.

[0018] Preferably, a drainage groove is provided on the side of the upper end of the liquid collecting tank, and the inner end of the drainage groove is connected to the liquid collecting tank, and the outer end of the drainage groove is connected to the outside of the reagent tank.

[0019] The above structural design can facilitate the discharge of residual reagents in the liquid collecting tank and the leakage hole.

[0020] Preferably, a sealing ring is provided on the lower surface of the reagent tank, the sealing ring coincides with the central axis of the through hole 1, and the diameter of the sealing ring is larger than the diameter of the through hole 1.

[0021] With the above structural design, a sealing ring is provided between the reagent tank and the rigid chip fixing plate to effectively seal the rigid chip fixing plate and the reagent tank, thereby preventing the subsequent added reagent from overflowing and preventing the reagent from flowing out from the gap between the reagent tank and the rigid chip fixing plate.

[0022] Preferably, the upper guide plate and the lower guide plate are both strip structures with an L-shaped cross-section.

[0023] With the above structural design, the guide plate is light in weight and high in strength, and the L-shaped cross section becomes groove-shaped after being tilted, which can be used to guide reagents.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] This suction filtration device uses a rigid chip with uniform pore size, strong selectivity, low filtrate residue, and no negative pressure suction filtration, which can effectively avoid cell stacking or compaction caused by excessive negative pressure during suction filtration, maintain the original state of the cells as much as possible, and improve the quality of CTC cell enrichment staining; the fixed component is light weight and strong, and the rigid chip is installed between the upper frame and the lower frame to avoid wrinkles and bubbles. The residual reagent in the chip can be removed by swinging and tilting the fixed component, facilitating automated operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1This is a schematic diagram of the three-dimensional structure of a fixing assembly according to an embodiment of the present invention.

[0027] Figure 2 Schematic diagram of the three-dimensional structure of the reagent tank carrying the microfluidic chip

[0028] Figure 3 yes Figure 2 Schematic diagram of the cross-sectional structure of the reagent tank shown.

[0029] Figure 4 It is a schematic diagram of the three-dimensional structure of the microfluidic chip.

[0030] Figure 5 It is a schematic diagram of the enlarged structure of some micropores in the microfluidic chip.

[0031] Figure 6 It is a schematic diagram of the three-dimensional structure of the liquid suction component.

[0032] Figure 7 It is a schematic diagram of the three-dimensional structure of the suction filter bin.

[0033] Figure 8 This is a cross-sectional view of the reagent tank, microfluidic chip, and suction filter chamber assembled together. DETAILED DESCRIPTION

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0035] The suction filtration device for CTC enrichment and staining of the present invention comprises a fixing component and a microfluidic chip mounted on the fixing component. The microfluidic chip comprises a reagent tank 1 and a rigid chip fixing plate 201 disposed below the reagent tank 1. Figure 1 As shown, the fixed assembly includes an upper frame 501 and a lower frame 502 arranged parallel to each other, with a left frame 503 and a right frame 504 arranged parallel to each other fixedly connected between the upper frame 501 and the lower frame 502, together forming a stable rectangular frame structure. The ends of the upper frame 501 and the lower frame 502 each extend a section beyond the left frame 503 and the right frame 504, and rollers 505 are installed at both ends of the upper frame 501 and the lower frame 502. The axes of the rollers 505 are parallel to the upper frame 501 or the lower frame 502. When in use, the two rollers on the left side can be installed in the same chute, and the two rollers on the right side can be installed in another chute, so that the fixed assembly can move along the chute. In addition, the driving mechanism can be used to lift one of the upper frame 501 and the lower frame 502 to tilt the fixed assembly to a certain angle.

[0036] An upper guide plate 506 and a lower guide plate 507 are fixedly connected to the side walls of the upper frame 501 and the lower frame 502 . The upper guide plate 506 and the lower guide plate 507 are both L-shaped strip structures or U-shaped strip structures in cross section.

[0037] To facilitate the installation of the roller 505, the upper frame 501 and the lower frame 502 are both long cylindrical structures. The upper guide plate 506 is welded or fixedly connected to the side of the upper frame 501 by screws, and the lower guide plate 507 is fixedly connected to the side of the lower frame 502. The upper guide plate 506 and the lower guide plate 507 are slightly shorter and are only located between the left frame 503 and the right frame 504. The two ends of the upper guide plate 506 are respectively connected to the inner upper ends of the left frame 503 and the right frame 504, and the two ends of the lower guide plate 507 are respectively connected to the inner lower ends of the left frame 503 and the right frame 504.

[0038] The left frame 503 and the right frame 504 are provided with upper guide holes 508 at positions corresponding to the upper guide plate 506, and lower guide holes 509 at positions corresponding to the lower guide plate 507. The upper guide holes 508 and the lower guide holes 509 are through-holes provided on the left frame 503 and the right frame 504, respectively, and are used to guide the test reagents inside the left frame 503 and the right frame 504 to the outside, where they are then collected by other guide devices for centralized disposal.

[0039] In addition, to improve strength and reduce weight, the side walls of the left frame 503 and the right frame 504 are fixedly connected with the left frame folding edge and the right frame folding edge 514 arranged opposite to each other. The left frame 503 and the left frame folding edge, and the right frame 504 and the right frame folding edge 514 form a right-angled folding structure, which has greater strength.

[0040] like Figure 1 As shown, during use, the rigid chip fixing plate 201 is attached to the bottom of the reagent reservoir 1. The rigid chip fixing plate 201 is in the form of a glass slide, and the rigid chip fixing plate 201 and the reagent reservoir 1 are clamped between the upper frame 501 and the lower frame 502. The width of the reagent reservoir 1 is less than the distance between the left frame 503 and the right frame 504. A single reagent reservoir 1 can be placed between the left frame 503 and the right frame 504, or multiple reagent reservoirs 1 can be placed side by side.

[0041] like Figure 2 、 Figure 3 As shown, the upper surface of the reagent tank 1 is provided with a liquid collecting groove 106, which is a funnel-shaped structure with a larger upper portion and a smaller lower portion. The lower end of the liquid collecting groove 106 is connected to a leakage hole 102, and the side of the upper end of the liquid collecting groove 106 is provided with a drainage groove 105. The inner end of the drainage groove 105 is connected to the liquid collecting groove 106, and the outer end is connected to the outside of the reagent tank 1. The lower end of the reagent tank 1 is detachably mounted with a suction filter 4 through a first card slot 103, as shown in FIG. Figure 7 As shown, the suction filter chamber 4 is a container with an upper opening and receiving the leakage hole 102; the rigid chip fixing plate 201 is located between the reagent tank 1 and the suction filter chamber 4; a through hole 1 202 is opened on the rigid chip fixing plate 201, and the chip body 2 is placed in the through hole 1 202.

[0042] When the reagent tank 1 is placed horizontally, the reagent or other liquid that drops through the leakage hole 102 passes through the chip body 2 and is collected in the suction filter chamber 4 .

[0043] like Figure 4 、 Figure 5 As shown, the material of the chip body 2 is preferably flexible glass, and a plurality of groups of long strip-shaped micropores are evenly distributed on the chip body 2; the micropores include horizontal holes 11 arranged horizontally and vertical holes 12 arranged longitudinally. The width of the horizontal hole 11 and the vertical hole 12 are both 0.0075mm, the length of the horizontal hole 11 is 0.09mm, and the length of the vertical hole 12 is 0.06mm. The horizontal holes 11 and the vertical holes 12 are arranged perpendicular to each other, the spacing between adjacent horizontal holes 11 is 0.03mm, the center of the vertical hole 12 is located on the center line of the horizontal hole 11, and the spacing between the upper ends of the horizontal holes 11 and the vertical holes 12 in the same hole group is 0.015mm. The spacing between adjacent vertical holes is large, which can effectively prevent cell overlap.

[0044] like Figure 6 、 Figure 8 As shown, a liquid absorption component 3 is provided on the lower surface of the rigid chip fixing plate 201. The liquid absorption component 3 includes a filter paper 301 adhered to the rigid chip fixing plate 201 and a polymer water-absorbing material layer 303 provided between the filter paper 301 and the microfluidic chip.

[0045] The polymer water-absorbing material layer 303 is made of powdered superabsorbent resin, a new type of functional polymer material. It has a high water absorption capacity, absorbing water hundreds to thousands of times its own weight, and has excellent water retention. Once it absorbs water and swells to form a hydrogel, even under pressure, it is difficult to separate the water. Superabsorbent resin is generally a polymer electrolyte containing hydrophilic groups and a cross-linked structure. Before absorbing water, the polymer chains entangle with each other and cross-link to form a network structure, thus achieving overall firmness. Upon contact with water, water molecules penetrate the resin through capillary action and diffusion, and the ionized groups on the chains ionize in the water. The electrostatic repulsion between the same ions on the chains causes the polymer chains to stretch and swell. Due to the requirement for electrical neutrality, counterions cannot migrate to the outside of the resin. The difference in ion concentration between the solution inside and outside the resin creates reverse osmotic pressure. Under the action of reverse osmotic pressure, water further enters the resin, forming a hydrogel.

[0046] like Figure 6 、 Figure 8As shown, a gasket 302 is provided between the lower surface of the rigid chip fixing plate 201 and the liquid absorption component 3, and the gasket 302 surrounds the polymer water-absorbing material layer 303. The function of the gasket 302 is to fix the powdered polymer material within the range of the gasket 302 to prevent the powdered polymer material from being too dispersed and affecting the water absorption effect. The filter paper 301 can be used in multiple layers. When in use, the layer of filter paper 301 farthest from the chip body 2 is fixed to the lower bottom surface of the rigid chip fixing plate 201. After the polymer water-absorbing material layer 303 absorbs enough reagent, it expands in volume, causing the liquid absorption component 3 to detach and fall into the suction filter chamber 4 under the action of gravity.

[0047] like Figure 2 、 Figure 3 As shown, in this embodiment, drainage grooves 105 are provided at two opposite corners along the length direction of the reagent tank 1. The drainage grooves 105 are located on both sides of the reagent tank 1 facing the upper frame 501 or the lower frame 502, and the outer ends of the drainage grooves 105 are connected to the outside of the reagent tank 1. In this way, after the cell staining is completed, the reagent tank 1 can be tilted by raising the upper frame 501 or the lower frame 502, and the excess reagent in the leakage hole 102 can be drained to the outside of the reagent tank 1 through the drainage grooves 105, and then flow along the upper guide plate 506 or the lower guide plate 507 to the outside of the left frame 503 and the right frame 504, which is conducive to the centralized disposal of waste reagents.

[0048] like Figure 7 、 Figure 8 As shown, the lower end of the reagent tank 1 is detachably mounted with a suction filter bin 4 through a first card slot 103. The suction filter bin 4 is a container with an upper opening and receives the leakage hole 102. The edge of the upper end of the suction filter bin 4 is provided with a claw 401 that matches the first card slot 103. When in use, the suction filter bin 4 can be installed to the lower end of the reagent tank 1 by simply inserting the claw 401 into the first card slot 103. After installation, the upper end opening of the suction filter bin 4 is opposite to the leakage hole 102, and the waste reagent flowing out of the leakage hole 102 through the chip body 2 and the liquid absorption component 3 falling off the chip body 2 are temporarily stored in the suction filter bin 4. After the cell enrichment process is completed, since the volume and weight of the polymer water-absorbing material increase significantly after absorbing water, the suction filter tank can prevent the polymer material from overflowing after absorbing water, reducing pollution to the surrounding environment. Precisely because the volume and weight of the polymer water-absorbing material increase significantly after absorbing water, the liquid absorption component 3 automatically falls off under the action of its gravity, eliminating the manual peeling step, reducing labor and avoiding pollution.

[0049] like Figure 8As shown, when in use, the rigid chip fixing plate 201 is fitted under the reagent tank 1, the liquid absorption component 3 is located under the chip body 2, and the suction filter chamber 4 is installed under the reagent tank 1. Blood or reagent is poured into the reagent tank 1, collected in the liquid collection tank 106, and then passes through the leakage hole 102 and the chip body 2. The blood or reagent that passes through the chip body 2 is absorbed by the liquid absorption component 3. The liquid absorption component contains a polymer water-absorbing material, and its volume expands hundreds of times after absorbing water. After absorbing the liquid, the liquid absorption component 3 is separated from the rigid chip fixing plate 201. The liquid absorption component 3 that has fully absorbed the reagent will eventually fall off the rigid chip fixing plate 201 and fall into the suction filter chamber 4. This is the cell enrichment process. Subsequently, at least one staining reagent is poured into the reagent tank 1. After staining with one staining reagent is completed, the drive device raises the upper frame 501 or the lower frame 502, and accordingly, one of the upper guide plates 506 or the lower guide plates 507 is raised. At this time, the reagent tank 1 tilts, and the reagent in the collection tank 106 flows along the lower drainage groove 105 into the lower upper guide plate 506 or lower guide plate 507, and finally flows along the guide plates to the outside of the left frame 503 or the right frame 504. Another staining reagent is then poured into the reagent tank 1, and the staining operation is repeated. The reagents in the collection tank 106 are finally collected and disposed of.

[0050] The contents not described in detail in this specification belong to the prior art known to those skilled in the art. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A suction filtration device for CTC enrichment and staining, comprising a fixed assembly and a microfluidic chip mounted on the fixed assembly, characterized in that: The microfluidic chip comprises a reagent tank (1), a rigid chip fixing plate (201) arranged at the lower end of the reagent tank (1), a through hole (202) being provided on the rigid chip fixing plate (201), a chip body (2) being placed in the through hole (202), the reagent tank (1) being a sheet-like structure with a liquid leakage hole (102) running longitudinally through the body thereof, and a liquid suction component (3) being provided on the lower surface of the rigid chip fixing plate (201); The chip body (2) is made of a transparent rigid material, and a plurality of groups of long strip-shaped micropores are evenly distributed on the chip body (2); the micropores on the chip body (2) include transverse holes (11) arranged transversely and vertical holes (12) arranged longitudinally; the widths of the transverse holes (11) and the vertical holes (12) are both 0.0075 mm, the length of the transverse holes (11) is 0.09 mm, and the length of the vertical holes (12) is 0.06 mm; the transverse holes (11) and the vertical holes (12) are arranged perpendicular to each other, the spacing between adjacent transverse holes (11) is 0.03 mm, the center of the vertical hole (12) is located on the center line of the transverse hole (11), and the spacing between the upper ends of the transverse holes (11) and the vertical holes (12) in the same hole group is 0.015 mm; The fixed assembly comprises an upper frame (501) and a lower frame (502) arranged in parallel with each other, a left frame (503) and a right frame (504) arranged in parallel with each other are fixedly connected between the upper frame (501) and the lower frame (502), rollers (505) are installed at both ends of the upper frame (501) and the lower frame (502), and an upper guide plate (506) and a lower guide plate (507) arranged opposite to each other are fixedly connected to the side walls of the upper frame (501) and the lower frame (502). The left frame (503) and the right frame (504) are provided with upper guide holes (508) at positions corresponding to the upper guide plate (506), and lower guide holes (509) at positions corresponding to the lower guide plate (507); the two ends of the rigid chip fixing plate (201) are overlapped on the upper guide plate (506) and the lower guide plate (507); the driving mechanism can be used to lift one of the upper frame (501) and the lower frame (502) to tilt the fixing assembly at a certain angle.

2. A suction filtration device for CTC enrichment and staining according to claim 1, characterized in that: The liquid absorption component (3) comprises a filter paper (301) adhered to the lower surface of the rigid chip fixing plate (201), and a polymer water-absorbing material layer (303) arranged between the filter paper (301) and the rigid chip fixing plate (201).

3. A suction filtration device for CTC enrichment and staining according to claim 2, characterized in that: The polymer water-absorbing material layer (303) of the liquid-absorbing component (3) covers the entire through hole 1 (202); a gasket (302) is provided between the lower surface of the rigid chip fixing plate (201) and the liquid-absorbing component (3); and the gasket (302) surrounds the polymer water-absorbing material layer (303).

4. The suction filtration device for CTC enrichment and staining according to claim 1, characterized in that: A suction filter bin (4) is detachably mounted on the lower end of the reagent tank (1) via a first card slot (103). The suction filter bin (4) is a container with an upper end opening and receiving the liquid leakage hole (102). The rigid chip fixing plate (201) is located between the reagent tank (1) and the suction filter bin (4).

5. The suction filtration device for CTC enrichment and staining according to claim 1, characterized in that: A funnel-shaped liquid collecting groove (106) is provided on the upper surface of the reagent tank (1), and the lower end of the liquid collecting groove (106) is connected to the liquid leakage hole (102).

6. A suction filtration device for CTC enrichment and staining according to claim 5, characterized in that: A drainage groove (105) is provided on the side of the upper end of the liquid collecting groove (106), and the inner end of the drainage groove (105) is connected to the liquid collecting groove (106), and the outer end is connected to the outside of the reagent tank (1).

7. The suction filtration device for CTC enrichment and staining according to claim 1, characterized in that: A sealing ring (107) is provided on the lower surface of the reagent tank (1), and the sealing ring (107) coincides with the central axis of the through hole 1 (202), and the diameter of the sealing ring (107) is larger than the diameter of the through hole 1 (202).

8. The suction filtration device for CTC enrichment and staining according to claim 1, characterized in that: The upper guide plate (506) and the lower guide plate (507) are both strip structures with L-shaped cross-sections.

Images