Application of Filter Membrane in Food and Medicine
Hawach membrane filter is the use of pressure as the driving force to rely on the selectivity of the membrane to separate the components in the liquid.
In food membrane filter, there are two filtration methods:
1. Standard membrane filter technology for filterable liquids.
2. HGMF (hydrophobic grid filter membrane) technology for gas.
When performing food membrane filter, the operations used are:
1. Collect and dilute the sample, and then select the appropriate medium and drop it into a Petri dish with a sterile absorbent pad to completely wet the absorbent pad.
2. Flame sterilize the forceps, then remove the filter membrane from the sterile packaging and place it in the filter funnel.
3. Flame sterilize the mouth of the sample container, then pour the sample into the filter funnel, and then open the vacuum filter device to allow the sample to completely filter the filter membrane by vacuuming.
4. Rinse the filter funnel with sterile buffer, and turn on the vacuum filter again to allow the liquid to completely filter the filter membrane by vacuuming.
5. Flame sterilize the tweezers and remove the filter membrane from the filter funnel.
6. Place the filter in the prepared petri dish and incubate at a specific temperature for a period of time. Then, count and confirm the colony, and issue a test report.
In terms of medicines, membrane filter is mainly used for sterility inspection. The method of inspection is to verify that the test product has antibacterial and antifungal properties for the membrane filter method. It is the same as the actual sterility inspection. Each filter in the same model Filter the specified amount of test products (the number of containers and the filtration volume per container) in the filter or filter cartridge, rinse the filter membrane with the eluent at least 3 times, the volume of each eluent is 100ml, and the next eluent In the test, enter the bacteria used for verification (inoculation volume is 10-100CFU); take another filter or filter cartridge without filtering the test sample, and repeat the above rinse operation as a positive control.
According to the specific situation, the entire filter or half of the filter can be transferred to 100ml of the designated verification medium, or the medium can be added to the filter cartridge equipped with the filter. Verify the strains listed in the table and the corresponding media one by one, and put the container at an appropriate temperature for cultivation, the cultivation time does not exceed 14d.
If you use a new filter or filter (including different manufacturers or batch numbers, models), you need to do according to the requirements of the above membrane filter method, group test, that is, sample test group, peptone control group and positive control group to re-verify and confirm.
Membrane filter method is not only used in the fields of food and medicine, but also in many fields such as chemical industry, electronics, energy, environmental protection, and inspection. It is very extensive. It is a branch of modern separation technology. The use of membrane filters can have purification, separation and concentration, and other technological purposes.