Rapid and lossless exosome extraction device

Abstract

The utility model discloses a rapid lossless exosome extraction device, which comprises a collection bottle and a funnel bottle arranged outside a bottle opening at the top end of the collection bottle, a filter membrane supporting disc is fixed in the bottle opening at the top end of the collection bottle, and a plurality of liquid leakage holes are formed in the filter membrane supporting disc at equal intervals. A filtering and extracting membrane is placed on the outer wall of the top end of the filtering membrane supporting disc, the filtering and extracting membrane is completely spread on the filtering membrane supporting disc, the novel auxiliary extracting device is additionally arranged in the funnel bottle, and the auxiliary extracting device has the remarkable beneficial effects that cell culture supernate can be uniformly distributed on the filtering and extracting membrane, so that the cell culture efficiency is improved, and the cell culture efficiency is improved. The damage to the membrane caused by overlarge local pressure and flow is avoided, the service life of the membrane is prolonged, the exosome interception and extraction efficiency is effectively improved, the exosome loss is reduced, the overall extraction efficiency is improved, the integrity and purity of the exosome can be guaranteed, the impurity interference is reduced, and a higher-quality sample is provided for subsequent research and application of the exosome; the development of related fields of biomedicine is powerfully promoted.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the biomedical related technical field, concretely relates to a kind of quick non-destructive exosome extraction device. BACKGROUND

[0002] Exosome, as a microvesicle secreted by cell, shows great application potential in numerous biomedical fields such as disease diagnosis, treatment and drug delivery. Therefore, efficient and accurate extraction of exosome is crucial for promoting research and development in related fields. In the existing exosome extraction technology, the problem of uniformity of filtration is prominent when using similar structural devices for extraction. In the traditional exosome extraction process, cell culture supernatant flows to the filtration extraction membrane through the funnel bottle, and due to the lack of effective dispersion and flow guide measures, uneven distribution of liquid often occurs. Specifically, liquid tends to concentrate in a local area of the filtration extraction membrane, causing excessive pressure and flow in that area, which may damage the filtration extraction membrane locally, affecting its service life and extraction efficiency.

[0003] At the same time, uneven distribution of liquid causes differences in exosome interception and extraction efficiency at different positions on the filtration extraction membrane. In the local area with excessive liquid flow, exosome may not be fully intercepted by the filtration extraction membrane and directly flow to the bottom of the collection bottle with the liquid, resulting in loss of exosome. In the area with smaller liquid flow, the extraction efficiency of exosome is low, and the entire area of the filtration extraction membrane cannot be fully utilized for exosome extraction, leading to low overall extraction efficiency. In addition, uneven filtration process may also affect the integrity and purity of exosome. Changes in local pressure and flow may damage the fragile structure of exosome, reducing its biological activity. At the same time, different residues of impurities in different areas also affect the purity of exosome, causing interference in subsequent research and application. SUMMARY

[0004] The utility model aims to provide a kind of quick non-destructive exosome extraction device to solve the problem of uneven filtration of cell culture supernatant when using similar devices in the existing exosome extraction technology. Specifically, liquid tends to concentrate in a local area of the filtration extraction membrane, causing excessive pressure and flow in that area, which may damage the filtration extraction membrane. Uneven distribution of liquid causes differences in exosome interception and extraction efficiency at different positions, resulting in loss of exosome and low overall extraction efficiency. Uneven filtration may also damage the integrity of exosome and affect its purity, causing interference in subsequent research and application.

[0005] In order to achieve the above object, the utility model provides the following technical scheme: a kind of quick non-destructive exosome extraction device, including collection bottle and funnel bottle being arranged at the outside of the top bottle mouth of collection bottle, the inside of the top bottle mouth of collection bottle is fixed with filter membrane support disc, multiple liquid leakage holes are equidistantly arranged in the inside of filter membrane support disc, filter extraction membrane is placed in the top outer wall of filter membrane support disc, filter extraction membrane is completely laid out on filter membrane support disc, the diameter of the bottom opening of funnel bottle is less than the diameter of top opening, auxiliary extraction device is arranged in the inside of funnel bottle.

[0006] Preferably, the auxiliary extraction device includes a small hole liquid outlet pipe head, an auxiliary inner cylinder, a placement disc, and a sight hole. The placement disc is placed at the top of the funnel bottle. A through hole is provided in the center of the placement disc. The auxiliary inner cylinder is fixed in the through hole. The auxiliary inner cylinder is vertically downward, and the auxiliary inner cylinder is vertically located in the center of the funnel bottle. Multiple small hole liquid outlet pipe heads are equidistantly arranged at the bottom of the auxiliary inner cylinder. The multiple small hole liquid outlet pipe heads are close to the annular outer wall of the bottom of the auxiliary inner cylinder, and the multiple small hole liquid outlet pipe heads are located above the filter extraction membrane.

[0007] Preferably, the auxiliary extraction device further includes a semicircular diffusion block, a vertical rod, and a semicircular diffusion cover. The semicircular diffusion block is fixed at the center of the inner wall of the bottom of the auxiliary inner cylinder. The vertical rod is provided at the center of the top of the semicircular diffusion block. The semicircular diffusion cover is fixed at the top of the vertical rod.

[0008] Preferably, the semicircular diffusion block and the semicircular diffusion cover are both semicircular in vertical cross-sectional shape. The diameter of the semicircular diffusion block is the same as the diameter of the semicircular diffusion cover. The semicircular diffusion block and the semicircular diffusion cover are both arranged in an upwardly arched state. The outer walls of the semicircular diffusion block and the semicircular diffusion cover are both smooth without burrs.

[0009] Preferably, the diameter of the semicircular diffusion block is smaller than the distance between the two symmetric small hole liquid outlet pipe heads. The multiple small hole liquid outlet pipe heads are arranged in a ring shape. The distance between the two symmetric small hole liquid outlet pipe heads is smaller than the diameter of the filter membrane support disc and the filter extraction membrane.

[0010] Preferably, an anti-skid bottom pad is further pasted to the outer wall of the bottom of the collection bottle. The anti-skid bottom pad is made of medical-grade soft rubber.

[0011] Preferably, a sealing retainer ring is sleeved and fixed to the outside of the lower side of the top bottle mouth of the collection bottle. A ring-shaped sealing gasket is provided on the top outer wall of the sealing retainer ring. The bottom outer wall of the funnel bottle can be completely attached to the top outer wall of the ring-shaped sealing gasket. The bottom circular inner wall of the funnel bottle and the outer wall of the top bottle mouth of the collection bottle are both provided with threads. The bottom of the funnel bottle is connected to the bottle mouth of the collection bottle through threads.

[0012] Preferably, the collecting bottle is provided with pressure relief valve and vacuum pressure relief valve at the upper left and right ends of the center, the vacuum pressure relief valve is connected with external vacuum pump to extract vacuum pressure in the collecting bottle, and rubber plug is installed outside the pressure relief valve when the collecting bottle is extracted vacuum pressure.

[0013] Compared with the prior art, the utility model provides a kind of quick lossless exosome extraction device, with the following beneficial effects:

[0014] The utility model discloses a funnel bottle is increased with novel auxiliary extraction device, when extracting exosome by injecting cell culture supernatant into the filtration extraction membrane protected by funnel bottle, only need to inject cell culture supernatant into the semicircle diffusion cover of auxiliary extraction device, when cell culture supernatant is injected into semicircle diffusion cover, semicircle diffusion cover arches upward and smooth outer wall without burr can make supernatant evenly flow along its surface to four directions, and then dispersed to the place of multiple small hole liquid outlet pipe head, since multiple small hole liquid outlet pipe head is annular arrangement and close to auxiliary inner cylinder bottom annular outer wall, supernatant will slowly and evenly drop from small hole liquid outlet pipe head to the filtration extraction membrane below, this process avoids the local excessive pressure caused by traditional direct pouring supernatant, prevents the local damage of filtration extraction membrane, to ensure the losslessness of exosome extraction process, and the setting of semicircle diffusion block further optimizes the dispersion effect of supernatant, when the supernatant dropping from small hole liquid outlet pipe head impacts semicircle diffusion block, semicircle diffusion block will change the flow direction of supernatant, so that supernatant spreads on filtration extraction membrane in a more gentle and more extensive way, to help cell culture supernatant more evenly distribute on filtration extraction membrane, greatly improve exosome extraction efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is the external three-dimensional structure schematic diagram of a kind of quick lossless exosome extraction device of the utility model.

[0016] Figure 2 It is the front plane structure schematic diagram of a kind of quick lossless exosome extraction device of the utility model.

[0017] Figure 3 It is the exploded three-dimensional structure schematic diagram of a kind of quick lossless exosome extraction device of the utility model.

[0018] Figure 4 It is the sectional three-dimensional structure schematic diagram of a kind of quick lossless exosome extraction device of the utility model.

[0019] Figure 5 It is the sectional three-dimensional structure schematic diagram of auxiliary extraction device of the utility model.

[0020] Figure 6 It is the bottom three-dimensional structure schematic diagram of auxiliary extraction device of the utility model.

[0021] In the figure: 1, anti-skid bottom pad; 2, collection bottle; 3, pressure relief valve port; 4, funnel bottle; 5, auxiliary extraction device; 6, vacuum pressure relief valve port; 7, sealing retainer ring; 8, filter membrane support disc; 9, filter extraction membrane; 10, liquid leakage hole; 11, ring-shaped sealing gasket; 12, small hole liquid outlet pipe head; 13, semicircular diffusion block; 14, vertical rod; 15, semicircular diffusion cover; 16, auxiliary inner cylinder; 17, placing disc; 18, sight hole. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the utility model will be apparently and completely described in connection with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the utility model.

[0023] The utility model provides a kind of fast nondestructive exosome extraction device as Figures 1-6 As shown in the figure, a kind of fast nondestructive exosome extraction device is provided, including collection bottle 2 and funnel bottle 4 arranged at the top bottle mouth outside of collection bottle 2, filter membrane support disc 8 is fixed in the top bottle mouth inside of collection bottle 2, multiple liquid leakage holes 10 are equidistantly arranged in the inside of filter membrane support disc 8, liquid leakage hole 10 can provide passageway for the smooth flow of subsequent liquid, filter extraction membrane 9 is placed on the top end outer wall of filter membrane support disc 8, filter extraction membrane 9 is completely laid out on filter membrane support disc 8, filter extraction membrane 9 is the key component of exosome extraction, needs to be completely laid out on filter membrane support disc 8, guarantees its uniformity and integrity, provides effective support for the interception of exosome, the opening diameter at the bottom end of funnel bottle 4 is less than the opening diameter at the top end, anti-skid bottom pad 1 is also pasted on the outer wall at the bottom end of collection bottle 2, anti-skid bottom pad 1 is made of medical grade soft rubber, anti-skid bottom pad 1 can make collection bottle 2 stably placed on operation plane, ensure that the device remains stable during operation.

[0024] As shown in the figure, Figure 1 , Figure 2 , Figure 3 And Figure 4As shown, the lower outside of the top end of the collection bottle 2 is sleeved and fixed with a sealing baffle 7, the top end outer wall of the sealing baffle 7 is provided with a ring-shaped sealing gasket 11, the bottom end outer wall of the funnel bottle 4 can be completely attached to the top end outer wall of the ring-shaped sealing gasket 11, the bottom end circular inner wall of the funnel bottle 4 and the top end bottle opening outer wall of the collection bottle 2 are both provided with threads, the bottom end of the funnel bottle 4 is connected with the bottle opening of the collection bottle 2 through threads, the funnel bottle 4 is installed outside the top end bottle opening of the collection bottle 2, the unique design of the bottom end opening diameter being smaller than the top end opening diameter is beneficial to guiding the liquid to flow to the filter extraction membrane 9 and can prevent the liquid from splashing to a certain extent, the funnel bottle 4 is connected with the collection bottle 2 through threads, and the bottom end outer wall of the funnel bottle 4 is tightly attached to the ring-shaped sealing gasket 11 at the top end of the sealing baffle 7, this sealing structure can ensure that the device forms a relatively closed space in the subsequent operation process, avoid external impurities from entering, and also prevent internal liquid from leaking, the upper side of the center of the collection bottle 2 is provided with a pressure relief valve port 3 and a vacuum pressure relief valve port 6 at both ends, the vacuum pressure relief valve port 6 is connected with an external vacuum pump and can extract vacuum and reduce pressure in the collection bottle 2, and a rubber plug needs to be installed outside the pressure relief valve port 3 when the collection bottle 2 is extracted vacuum and reduced pressure, the pressure relief valve port 3 and the vacuum pressure relief valve port 6 provide a key channel for controlling the pressure in the collection bottle 2, in the preparation stage, the vacuum pressure relief valve port 6 is connected with the external vacuum pump, so as to extract vacuum and reduce pressure in the collection bottle 2, and in the vacuum extraction process, a rubber plug needs to be installed outside the pressure relief valve port 3, to ensure that the pressure in the device is stable.

[0025] As Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, in the use of the present quick and lossless exosome extraction device, first, the cell culture supernatant after preliminary filtration by the filter membrane is to be treated, then the collection bottle 2 is stably placed in the appropriate position by the anti-skid bottom pad 1, then the rubber plug is tightly installed on the pressure relief valve port 3, then the new filter extraction membrane 9 is carefully taken out with tweezers and placed on the filter membrane support disc 8, and the front surface (i.e. the shiny surface) of the filter extraction membrane 9 must be upward during the placement process, then the position of the filter extraction membrane 9 is carefully adjusted to eliminate its wrinkles, so that the filter extraction membrane 9 is completely flat on the filter membrane support disc 8, then the funnel bottle 4 is connected and installed with the collection bottle 2, the bottom end of the funnel bottle 4 is sleeved outside the top bottle port of the collection bottle 2, and is slowly screwed by threads until the bottom end of the funnel bottle 4 is tightly fitted on the ring-shaped sealing gasket 11 at the top end of the sealing baffle 7, to ensure that the sealing performance of the device is good, then the vacuum pressure reducing valve port 6 is connected with the vacuum pressure reducing pump through the pipeline, and the vacuum pressure reducing pump is started, then a proper amount of PBS is sucked by the special suction tube and slowly added to the filter extraction membrane 9, this step is mainly to perform hydrophilic treatment on the filter extraction membrane 9 to improve the subsequent extraction effect, after the PBS completely passes through the filter extraction membrane 9, a proper amount of cell culture supernatant is added, at this time, the auxiliary extraction device 5 is used to uniformly place the cell culture supernatant on the filter extraction membrane 9, since the inside of the collection bottle 2 is in a negative pressure state, it will produce a downward drainage effect (i.e. pressure reduction filtration) on the cell culture supernatant, when the cell culture supernatant is completely filtered, the exosomes are left on the filter extraction membrane 9, then a proper amount of PBS is added for pressure reduction filtration and cleaning, this cleaning step needs to be repeated three times to sufficiently remove impurities, after cleaning is completed, the auxiliary extraction device 5 is removed, and a proper amount of PBS is sucked by the pipette gun to flow uniformly through the filter extraction membrane 9, so as to recover the exosomes remaining on the surface of the filter extraction membrane 9, then the PBS flowing through the surface of the filter extraction membrane 9 is re-sucked and repeatedly operated to ensure that all exosomes on the filter extraction membrane 9 can be completely extracted and recovered, finally, the PBS containing exosomes sucked by the pipette gun is recovered into a special micro-tube, and thus the exosome extraction work is completed.

[0026] As Figure 1 , Figure 5 and Figure 6As shown, the funnel bottle 4 is internally provided with an auxiliary extraction device 5, and the auxiliary extraction device 5 in the exosome extraction device is designed and cooperated in a unique structure and mode, aiming to realize more uniform distribution of cell culture supernatant on the filtration extraction membrane 9, and further improve the efficiency and quality of exosome extraction. The auxiliary extraction device 5 includes a small hole liquid outlet pipe head 12, an auxiliary inner cylinder 16, a placement disc 17 and a sight glass 18. The placement disc 17 is placed at the top end of the funnel bottle 4, and the placement disc 17 can provide stable support for the auxiliary extraction device 5. The center of the placement disc 17 is internally provided with a perforation, and the auxiliary inner cylinder 16 is fixed in the perforation. The auxiliary inner cylinder 16 is vertically downward, and the auxiliary inner cylinder 16 is vertically located in the center of the funnel bottle 4. A plurality of small hole liquid outlet pipe heads 12 are equidistantly arranged at the bottom end of the auxiliary inner cylinder 16. The plurality of small hole liquid outlet pipe heads 12 are close to the annular outer wall of the bottom end of the auxiliary inner cylinder 16, and the plurality of small hole liquid outlet pipe heads 12 are located above the filtration extraction membrane 9. When the cell culture supernatant is injected into the auxiliary extraction device 5, it first enters the auxiliary inner cylinder 16. The plurality of small hole liquid outlet pipe heads 12 equidistantly arranged at the bottom end of the auxiliary inner cylinder 16 are close to the annular outer wall of the bottom end of the auxiliary inner cylinder 16. This design is the key to realize the initial dispersion of the liquid. The supernatant slowly flows out from the plurality of small hole liquid outlet pipe heads 12 under the action of gravity and the internal pressure of the auxiliary inner cylinder 16. Since the small hole liquid outlet pipe heads 12 are arranged in a ring shape, the supernatant can be evenly scattered on the filtration extraction membrane 9 below in a ring shape, avoiding the problem of concentrated impact and uneven distribution caused by the traditional single outlet. The pressure on the filtration extraction membrane 9 is effectively reduced, preventing damage to the membrane and ensuring the lossless nature of the exosome extraction process.

[0027] As Figure 1 , Figure 5 and Figure 6As shown, the auxiliary extraction device 5 further comprises a semicircular diffusion block 13, a vertical rod 14 and a semicircular diffusion cover 15, the semicircular diffusion block 13 is fixed at the center of the inner wall of the bottom end of the auxiliary inner cylinder 16, the vertical rod 14 is arranged at the center of the top end of the semicircular diffusion block 13, the semicircular diffusion cover 15 is fixed at the top end of the vertical rod 14, the vertical section shape of the semicircular diffusion block 13 and the semicircular diffusion cover 15 is semicircular, the diameter of the semicircular diffusion block 13 and the semicircular diffusion cover 15 is the same, the semicircular diffusion block 13 and the semicircular diffusion cover 15 are arranged in an upwardly arched state, the outer wall of the semicircular diffusion block 13 and the semicircular diffusion cover 15 is smooth without burrs, when the cell culture supernatant flowing out from the small hole liquid outlet pipe head 12 impacts on the semicircular diffusion cover 15, the smooth outer wall of the semicircular diffusion cover 15 causes the supernatant to disperse in all directions along the surface thereof, due to the upwardly arched shape of the semicircular diffusion cover 15, the supernatant is guided in different directions, thereby further expanding the distribution range of the liquid, then the supernatant continues to flow downward to the semicircular diffusion block 13, the semicircular diffusion block 13 changes the flow direction of the supernatant again, so that the supernatant is diffused on the filtration extraction membrane 9 in a more gentle and more extensive manner, the diameter of the semicircular diffusion block 13 is smaller than the distance between the two symmetrical small hole liquid outlet pipe heads 12, the plurality of small hole liquid outlet pipe heads 12 are arranged in a ring shape, and the distance between the two symmetrical small hole liquid outlet pipe heads 12 is smaller than the diameter of the filter membrane support disc 8 and the filtration extraction membrane 9, the diameter of the semicircular diffusion block 13 is smaller than the distance between the two symmetrical small hole liquid outlet pipe heads 12, which ensures that the supernatant flowing out from different small hole liquid outlet pipe heads 12 does not interfere with each other when reaching the semicircular diffusion cover 15 and the semicircular diffusion block 13, and can independently diffuse respectively, at the same time, the plurality of small hole liquid outlet pipe heads 12 are arranged in a ring shape, and the distance between the two symmetrical small hole liquid outlet pipe heads 12 is smaller than the diameter of the filter membrane support disc 8 and the filtration extraction membrane 9, so that the supernatant dispersed by the auxiliary extraction device 5 can completely cover the effective working area of the filtration extraction membrane 9, fully utilize the area of the filtration extraction membrane 9 for exosome extraction, and greatly improve the extraction efficiency.

[0028] Finally, it should be noted that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Although the present application 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 make equivalent replacements to some technical features, as long as they are within the spirit and principles of the present application. Any modification, equivalent replacement, improvement, etc. made within the scope of the present application shall be included in the protection scope of the present application.

Claims

1. A rapid non-destructive exosome extraction device, comprising a collection bottle (2) and a funnel bottle (4) arranged outside the top bottle opening of the collection bottle (2), a filter membrane support disc (8) is fixed inside the top bottle opening of the collection bottle (2), a plurality of liquid leakage holes (10) are arranged equidistantly inside the filter membrane support disc (8), a filter extraction membrane (9) is placed on the top end outer wall of the filter membrane support disc (8), the filter extraction membrane (9) is completely laid out on the filter membrane support disc (8), and the bottom opening diameter of the funnel bottle (4) is smaller than the top opening diameter, characterized in that: The funnel bottle (4) is internally provided with an auxiliary extraction device (5); The auxiliary extraction device (5) comprises a small-hole liquid outlet pipe head (12), an auxiliary inner cylinder (16), a placing disc (17) and a sight hole (18), the placing disc (17) is placed at the top end of the funnel bottle (4), the center of the placing disc (17) is internally provided with a perforation, the auxiliary inner cylinder (16) is fixed in the perforation, the auxiliary inner cylinder (16) vertically faces downward, and the auxiliary inner cylinder (16) is vertically located in the center of the funnel bottle (4), a plurality of small-hole liquid outlet pipe heads (12) are equidistantly arranged at the bottom end of the auxiliary inner cylinder (16), the plurality of small-hole liquid outlet pipe heads (12) are close to the annular outer wall of the bottom end of the auxiliary inner cylinder (16), and the plurality of small-hole liquid outlet pipe heads (12) are located above the filter extraction membrane (9).

2. The rapid non-invasive exosome extraction device of claim 1, wherein: The auxiliary extraction device (5) further comprises a semicircular diffusion block (13), a vertical rod (14) and a semicircular diffusion cover (15), the semicircular diffusion block (13) is fixed at the center of the inner wall of the bottom end of the auxiliary inner cylinder (16), the vertical rod (14) is arranged at the center of the top end of the semicircular diffusion block (13), and the semicircular diffusion cover (15) is fixed at the top end of the vertical rod (14).

3. The device for rapid non-invasive exosome extraction according to claim 2, wherein: The semicircular diffusion block (13) and the semicircular diffusion cover (15) are both semicircular in vertical cross-sectional shape, the diameter of the semicircular diffusion block (13) is the same as that of the semicircular diffusion cover (15), the semicircular diffusion block (13) and the semicircular diffusion cover (15) are both arranged in an upwardly arched state, and the outer walls of the semicircular diffusion block (13) and the semicircular diffusion cover (15) are smooth without burrs.

4. The device for rapid non-invasive exosome extraction according to claim 3, wherein: The diameter of the semicircular diffusion block (13) is smaller than the distance between the two symmetrical small-hole liquid outlet pipe heads (12), the plurality of small-hole liquid outlet pipe heads (12) are arranged in a ring shape, and the distance between the two symmetrical small-hole liquid outlet pipe heads (12) is smaller than the diameter of the filter membrane support disc (8) and the filter extraction membrane (9).

5. The rapid non-invasive exosome extraction device of claim 1, wherein: The outer wall of the bottom end of the collecting bottle (2) is further pasted with an anti-skid bottom pad (1) made of medical-grade soft rubber.

6. The rapid non-invasive exosome extraction device of claim 1, wherein: The outer wall of the bottom end of the funnel bottle (4) can be completely attached to the outer wall of the top end of the collecting bottle (2), and the outer wall of the bottom end of the funnel bottle (4) and the outer wall of the top end of the collecting bottle (2) are both provided with threads, and the bottom end of the funnel bottle (4) is connected to the bottle opening of the collecting bottle (2) through the threads.

7. The rapid non-invasive exosome extraction device of claim 1, wherein: The center of the collecting bottle (2) is provided with a pressure relief valve opening (3) and a vacuum pressure relief valve opening (6) at the upper side of the left and right ends, respectively, the vacuum pressure relief valve opening (6) is connected to an external vacuum pump to extract vacuum and reduce pressure in the collecting bottle (2), and a rubber plug is required to be installed outside the pressure relief valve opening (3) when the collecting bottle (2) is extracted vacuum and reduced pressure.

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