Sterilizing and filtering device for liquid culture medium
Through the two-stage microporous filter membrane filtration system, the liquid culture medium is filtered step by step by step using the primary filtration component and the two-stage microporous filter membrane module, which solves the problems of unstable pressure, high pollution risk and complex operation of the existing sterilization and filtration methods, and achieves the effects of efficient sterilization, simplified operation and stable pH.
Patent Information
- Application Number
- CN202420587179.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-25
- Publication Date
- 2025-03-07
- Estimated Expiration
- 2034-03-25
AI Technical Summary
The existing liquid culture medium sterilization and filtration methods have problems such as unstable pressure, high pollution risk, complex operation and slow filtration speed. Especially, high-temperature insufficiency culture medium is difficult to pass high-temperature autoclave, resulting in unsatisfactory sterilization of sterilization.
A two-stage microporous filter membrane filtration system is adopted. The primary filter assembly is used to remove impurities with particle sizes greater than 10 microns. The filter membrane pore size of the first microporous filter membrane module is 0.45 to 0.5 microns, and the filter membrane pore size of the second microporous filter membrane module is 0.1 to 0.22 microns. The liquid culture medium is filtered step by step through a peristaltic pump to avoid the use of compressed air and carbon dioxide.
It achieves efficient sterilization, reduces the risk of pollution, simplifies the operation process, avoids changes in pH value, improves filtration efficiency and equipment service life, and passes the sterile inspection of the filtered culture medium.
Smart Images
Figure CN222574642U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of biomedicine, in particular to a liquid culture medium sterilization and filtering device. Background Art
[0002] Culture medium is a kind of nutrient prepared by artificial production that is suitable for the growth and reproduction of microorganisms, cells, etc. Because it contains more nutrients such as carbon source, vitamins, inorganic salts, nitrogen source, etc., it is easily disturbed by the external storage environment or contaminated by bacteria during the preparation process, causing the culture medium to deteriorate. According to the physical state, culture medium can generally be divided into liquid culture medium, solid culture medium and semi-solid culture medium. In many microbial experiments and cell experiments, liquid culture medium is often used and sterile is required. The experimental environment and reagent consumables must be guaranteed not to be affected by other microorganisms and harmful factors. Common contamination of liquid culture medium includes bacterial contamination and fungal contamination. When the culture medium is contaminated by bacteria, the culture medium becomes turbid and deteriorates, and the pH changes. Bacterial contamination of culture medium can lead to poor cell growth and pathological changes until death. When the culture medium is contaminated by fungi, small white or yellow spots can be seen with the naked eye, and large pieces of suspended matter can be seen in severe cases. Unlike bacterial contamination, the culture medium contaminated by fungi does not become turbid; but under an inverted biological microscope, dendritic or filamentous hyphae can be seen interlaced between cells and culture medium. When cells are contaminated by fungi, they do not die immediately but grow slowly, and eventually die due to nutrient consumption and cytotoxicity. Therefore, the culture medium used for cell culture needs to be strictly sterilized after preparation before it can be used. However, because the culture medium often contains a large amount of nutrients such as vitamins and proteins that are not resistant to high-temperature sterilization, most of them cannot be sterilized by high-temperature and high-pressure methods. Therefore, filtration sterilization has become the most common sterilization method for liquid culture media.
[0003] Liquid culture media that are not resistant to high temperatures can be filtered and sterilized using a 0.1-0.2um microporous filter. Common filtration methods include positive pressure filtration and negative pressure filtration. Positive pressure filtration uses external force or air pressure to block liquid culture media from passing through the filter layer and contaminants outside the membrane. Negative pressure filtration is achieved by connecting a vacuum pump above the container. The vacuum pump sucks away the air inside the container to create a negative pressure inside, and the liquid can flow from the top through the filter layer into the container below. Both positive and negative pressure filtration require a filter membrane. The size and area of the pores of the filter membrane directly affect the filtration effect and filtration speed.
[0004] Positive pressure filtration requires the use of compressed air or carbon dioxide to increase the pressure to allow the liquid to pass through the microporous filter membrane. Unstable pressure can cause the microporous filter membrane to break through, thereby increasing the risk of contamination. In addition, compressed air and carbon dioxide may contain other impurity gases that affect the stability and pH of the culture medium. Negative pressure filtration requires the use of a vacuum pump, which has high requirements for container sealing and requires frequent replacement of the collection medium container. The operation is complicated and there is no way to pause from the start of filtration of a bottle to the end of filtration of the bottle. In addition, the above two filtration methods are affected by the size of the microporous filter membrane area, resulting in slow filtration speed, small filtration volume, and the need to frequently replace the microporous filter membrane, increasing the cost of use. Utility Model Content
[0005] The utility model aims to provide a liquid culture medium sterilization and filtration device to solve the above problems.
[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:
[0007] A liquid culture medium sterilization filtration device, which may include:
[0008] A primary filtration component, the primary filtration component is used to remove impurities with a particle size greater than 10 microns in the liquid culture medium;
[0009] a first microporous filter membrane assembly, wherein the liquid inlet of the first microporous filter membrane assembly is in fluid communication with the primary filter assembly via a hose;
[0010] A peristaltic pump, wherein the hose is mounted on the peristaltic pump;
[0011] A second microporous filter membrane component, wherein the liquid inlet of the second microporous filter membrane component is fluidically connected to the liquid outlet of the first microporous filter membrane component, and the filter membrane pore size of the second microporous filter membrane component is smaller than the filter membrane pore size of the first microporous filter membrane component.
[0012] In one embodiment, the primary filter component is a PP cotton filter element.
[0013] In one embodiment, the pore size of the filter membrane of the first microporous filter membrane assembly is 0.45 to 0.5 microns.
[0014] In one embodiment, the pore size of the filter membrane of the second microporous filter membrane assembly is 0.1-0.22 microns.
[0015] In one embodiment, the filter membranes of the first microporous filter membrane assembly and the second microporous filter membrane assembly are PES filter membranes.
[0016] In one embodiment, the filter membranes in the first microporous filter membrane assembly and the second microporous filter membrane assembly are folded.
[0017] In one embodiment, the filter membrane is folded into 3 layers.
[0018] In one embodiment, the first microporous filter membrane assembly is provided with an exhaust valve.
[0019] In one embodiment, a protective cover is installed at the liquid outlet of the second microporous filter membrane assembly.
[0020] In one embodiment, the hose is made of silicone.
[0021] The utility model adopts the above technical scheme, and has the beneficial effects of simple structure, easy use, less influence of external factors on the culture medium filtered by the utility model, stable pH after filtration, no need to replace the microporous filter membrane in the middle, avoiding the risk of contamination, and passing the sterility inspection. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 It is a schematic diagram of a liquid culture medium sterilization and filtration device according to an embodiment of the utility model. DETAILED DESCRIPTION
[0023] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings so that the purpose, features and advantages of the present invention can be more clearly understood. It should be understood that the embodiments shown in the accompanying drawings are not intended to limit the scope of the present invention, but are only intended to illustrate the essential spirit of the technical solution of the present invention.
[0024] In the following description, certain specific details are set forth for the purpose of illustrating various disclosed embodiments to provide a thorough understanding of the various disclosed embodiments. However, those skilled in the relevant art will recognize that the embodiments may be practiced without one or more of these specific details. In other cases, well-known devices, structures, and techniques associated with the present application may not be shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.
[0025] Unless the context requires otherwise, throughout the specification and claims, the word "comprise" and variations such as "include" and "have" should be construed in an open, inclusive sense, ie, should be interpreted as "including, but not limited to."
[0026] References throughout the specification to "one embodiment" or "an embodiment" indicate that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of "in one embodiment" or "in an embodiment" in various places throughout the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any manner in one or more embodiments.
[0027] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. It should be noted that the term "or" is generally employed in its sense including "and / or" unless the context clearly dictates otherwise.
[0028] In the following description, in order to clearly demonstrate the structure and working mode of the utility model, many directional words will be used for description, but the words "front", "back", "left", "right", "outside", "inside", "outward", "inward", "up", "down", etc. should be understood as convenient terms and should not be understood as restrictive terms.
[0029] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.
[0030] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0031] like Figure 1As shown, a liquid culture medium sterilization filtration device according to an embodiment of the utility model may include a primary filter component 1, a first microporous filter membrane component 2, a second microporous filter membrane component 3 and a peristaltic pump 4. Among them, the primary filter component 1 is used to remove impurities with a particle size greater than 10 microns in the liquid culture medium, for example, to filter out larger impurities that may be mixed in the preparation process and some undissolved particles in the culture medium, so as to avoid entering the microporous filter membrane and causing blockage to affect the filtering effect. The liquid inlet of the first microporous filter membrane component 2 is fluidly connected to the primary filter component 1 through a hose 5. The hose 5 is installed on the peristaltic pump 4 to pump the liquid culture medium passing through the primary filter component 1 into the first microporous filter membrane component 2 through the peristaltic pump 4. When it is necessary to temporarily interrupt the filtration, it is only necessary to shut down the peristaltic pump 4, which is very convenient. The liquid inlet of the second microporous filter membrane component 3 is fluidly connected to the liquid outlet of the first microporous filter membrane component 2, for example, directly connected or connected through a hose. The pore size of the second microporous membrane filter assembly 3 is smaller than that of the first microporous membrane filter assembly 2, so as to further filter out impurities with smaller particle sizes. The two-stage filtration of the first microporous membrane filter assembly 2 and the second microporous membrane filter assembly 3 effectively avoids the problem of bacterial and fungal contamination of the culture medium due to insufficient filtration. At the same time, since compressed air and carbon dioxide are not used in the filtration process, the original pH of the culture medium will not be affected.
[0032] For example, the primary filter assembly 1 can be composed of a PP cotton filter element. The PP cotton filter element can filter out large-size particles in the liquid culture medium to avoid clogging the subsequent microporous filtration membrane assembly. When in use, the primary filter assembly 1 is immersed in the culture medium to be filtered.
[0033] The first microporous filter membrane assembly 2 and the second microporous filter membrane assembly 3 have the same structure, both comprising a housing and a microporous filter membrane placed in the housing, and the housing is provided with a corresponding liquid inlet and liquid outlet. The housing can be configured to be detachable to facilitate replacement of the microporous filter membrane. It should be understood that the first microporous filter membrane assembly 2 and the second microporous filter membrane assembly 3 can also be filter cartridge products available on the market.
[0034] The pore size of the filter membrane of the first microporous filter membrane component 2 is 0.45 to 0.5 microns, which can effectively filter out solid particles with a diameter greater than 0.45 microns, such as sediments, suspended matter, impurities and some bacteria. The pore size of the filter membrane of the second microporous filter membrane component 3 is 0.1 to 0.2 microns, which can further filter out bacteria in the liquid. In a specific embodiment, the filter membranes of the first microporous filter membrane component 2 and the second microporous filter membrane component 3 are 0.45 micron and 0.2 micron PES filter membranes, respectively. It should be understood that the first microporous filter membrane component 2 and the second microporous filter membrane component 3 can also be composed of filter membranes of other specifications and materials.
[0035] In order to further improve the filtering effect, the filter membranes in the first microporous filter membrane assembly 2 and the second microporous filter membrane assembly 3 are folded and placed. Preferably, the filter membrane is folded into 2-5 layers; more preferably, the filter membrane is folded into 3 layers. The filter membrane is folded and placed, which can increase the effective filtering area by 2 to 4 times compared with the original solution of laying flat, greatly improving the filtering efficiency.
[0036] The first microporous membrane filter assembly 2 is usually placed above the second microporous membrane filter assembly 3, so that the liquid culture medium after passing through the first microporous membrane filter assembly 2 can flow into the second microporous membrane filter assembly 3 under the action of gravity, and the liquid culture medium after being filtered by the second microporous membrane filter assembly 3 can be conveniently collected in the culture medium bottle below it. In this case, the first microporous membrane filter assembly 2 and the second microporous membrane filter assembly 3 are usually fixedly mounted on a bracket (not shown) to ensure that they can be placed vertically.
[0037] An exhaust valve 6 is installed on the first microporous filter membrane assembly 2. During the filtering process, when gas enters the first microporous filter membrane assembly 2, the exhaust valve 6 can be opened to exhaust excess air to avoid affecting the filtering effect.
[0038] A protective cover 7 is installed at the liquid outlet of the second microporous filter membrane assembly 3 to prevent foreign matter from falling into the liquid culture medium bottle 8 below it. The protective cover 7 can be made of plastic to facilitate observation of whether the culture medium bottle 8 is full.
[0039] The peristaltic pump 4 can be purchased from the market, and its structure is well known and will not be described in detail here.
[0040] In a specific embodiment, the hose 5 is a silicone hose, which has the advantage of a long service life.
[0041] The working process of the novel method is described below: first, immerse the primary filter assembly into the liquid culture medium to be filtered, turn on the peristaltic pump 4, and pump the liquid culture medium into the first microporous filter membrane assembly 2 through the silicone hose for filtration to remove impurities and bacteria with a diameter of more than 0.45 microns. The liquid culture medium filtered by the first microporous filter membrane assembly 2 then enters the second microporous filter membrane assembly 3 for further filtration to remove bacteria in the liquid culture medium; finally, the liquid culture medium filtered by the second microporous filter membrane assembly 3 flows out from the liquid outlet and is collected in the culture medium bottle 8. When the liquid in the culture medium bottle reaches the scale, or the filtration needs to be stopped midway, the peristaltic pump 4 can be paused. The entire operation process is very simple, and the filtering effect is good.
[0042] After various liquid culture medium filtration experiments, it can be concluded that the culture medium filtered by the utility model device can effectively filter bacteria and fungi with a diameter of more than 0.2 microns, and the original pH of the culture medium will not be changed after filtration. The results are shown in the following table:
[0043] Culture medium name PH before filtration After filtering Sterility test RPMI1640 7.2 7.2 Sterile DMEM 7.2 7.2 Sterile CD293 7.0 7.0 Sterile
[0044] The preferred embodiments of the present invention have been described in detail above, but it should be understood that after reading the above teachings of the present invention, those skilled in the art may make various changes or modifications to the present invention. These equivalent forms also fall within the scope defined by the claims attached to this application.
Claims
1. A liquid culture medium sterilization filtration device, characterized in that: include: A primary filtration component, the primary filtration component is used to remove impurities with a particle size greater than 10 microns in the liquid culture medium; a first microporous filter membrane assembly, wherein the liquid inlet of the first microporous filter membrane assembly is in fluid communication with the primary filter assembly via a hose; a peristaltic pump, the peristaltic pump being mounted on the hose; A second microporous filter membrane component, wherein the liquid inlet of the second microporous filter membrane component is fluidically connected to the liquid outlet of the first microporous filter membrane component, and the filter membrane pore size of the second microporous filter membrane component is smaller than the filter membrane pore size of the first microporous filter membrane component.
2. The liquid culture medium sterilization filtration device according to claim 1, characterized in that: The primary filter component is a PP cotton filter element.
3. The liquid culture medium sterilization filtration device according to claim 1, characterized in that: The pore size of the first microporous filter membrane assembly is 0.45 to 0.5 microns.
4. The liquid culture medium sterilization filtration device according to claim 1, characterized in that: The pore size of the second microporous filter membrane assembly is 0.1 to 0.22 microns.
5. The liquid culture medium sterilization filtration device according to claim 1, characterized in that: The first microporous filter membrane assembly and the second microporous filter membrane assembly are composed of PES filter membranes.
6. The liquid culture medium sterilization filtration device according to claim 1, characterized in that: The filter membranes in the first microporous filter membrane assembly and the second microporous filter membrane assembly are folded and placed.
7. The liquid culture medium sterilization filtration device according to claim 6, characterized in that: The filter membrane was folded into 3 layers.
8. The liquid culture medium sterilization filtration device according to claim 1, characterized in that: The first microporous filter membrane assembly is provided with an exhaust valve.
9. The liquid culture medium sterilization filtration device according to claim 1, characterized in that: A protective cover is installed at the liquid outlet of the second microporous filter membrane assembly.
10. The liquid culture medium sterilization filtration device according to claim 1, characterized in that: The hose is made of silicone.