.

Quality Control of Culture Media for Food Microbiology

First, quality control of culture media for food microbiologyin preparation:

(1) Container: the flask, plate, test tube and other equipment for preparing and repacking the culture medium shall be neutral, free of acid and alkali inhibitor residues, and the bottom of the plate shall be flat, so as to avoid the different thickness of agar and affect the drug sensitivity test results.

(2) Ingredient source: all kinds of ingredients are reliable and do not contain substances that inhibit the growth of the target bacteria. Special requirements of the culture medium, such as glucose oxidation fermentation test (O / F test), in addition to adding glucose, can not contain other sugars, and indicators can not use alcohol solution to avoid false-positive in the O / F test. The water for medium preparation shall be distilled water.

(3) PH value adjustment: adjust the pH value according to different requirements of the medium, and control it within ± 0.2 of the required range. It should be noted that the pH value of the medium decreased by 0.1-0.2 after autoclaving, so the pH value should be 0.1-0.2 higher than the actual need.

(4) Sterilization: different sterilization methods shall be selected according to the different components and preparation quantity of the culture medium, so as to achieve the sterilization effect without damaging the components of the culture medium. In general, the stable medium can be sterilized under high pressure, i.e. 121 ℃ for 15 minutes, while the medium containing sugar should be sterilized at 108 ℃ to prevent the destruction of sugar. Materials that are not resistant to high heat, such as serum and milk, can be sterilized by interval sterilization.

(5) Subpackage: determine the subpackage quantity according to the purpose and requirements of use. The plates and test tubes used for subpackage of the culture medium shall be clean and free of acid and alkali residues; when preparing the plate culture medium, the operating platform shall be level to avoid the different thickness of the agar plate and ensure aseptic operation.

Second, quality control of culture mediafor food microbiology after preparation;

  

(1) The appearance of medium: it includes color, transparency, precipitation and coagulation. If cracks are found on the surface of the medium or it is separated from the edge of the dish, it means that the medium is dehydrated and must be discarded.

(2) Sterility test: sterility test shall be carried out for each batch of prepared medium. The culture medium sterilized first and then repacked can be tested by sampling method. The selective culture gene contains inhibitory substances, which can inhibit many microorganisms. Therefore, 10 times of sterile liquid medium can be added to dilute the inhibitory substances in order to detect the contaminating bacteria. Even after the sterility test, check the visible colony on each plate when inoculating.

(3) Performance test: before using each batch of newly made or newly purchased culture medium, it is necessary to take the known nature of the stock bacteria for the performance tests. According to different purposes, the medium can be divided into enrichment medium, isolation medium and identification medium.

① Enrichment medium: inoculate a small number of bacteria that are difficult to grow, and observe the enrichment within a certain period of time. The smaller the minimum inoculation concentration that bacteria can grow, the better the performance of the enrichment medium.

② Isolation medium: the target bacteria should grow well and the non-target bacteria should be inhibited. Generally, the inoculation amount of the target bacteria required to grow should not be too much. The better method is to adjust the test bacteria to a bacterial suspension with a turbidity of 0.5 MC and then smear it on the culture medium with a standard inoculation ring of 0.001ml to observe the growth of the colonies.

  

③ Identification medium: strains with typical characteristics should be selected for the performance tests.

Our company provides swab sampler,welcome to order.



Отправить запрос, связаться с поставщиком

Кому: Elex Biological Products (Shanghai) Co., Ltd.
Ваш E-mail:
Текст письма:


Send to other suppliers

Другие товары поставщика

Colony Counter
Colony Counter Performance Characteristics of Contact Agar Based Medium4x4 Microbiology Agar Medium Types AC • Standard Plate Counting Agar Based Medium Used...
Agar Stamp  AC	Total Bacteria Count Agar, 10cm²	10pcs/bag; 100pcs/box	48±2 hours	6 months Agar Stamp  EC	Coliform group&E.coli Count Agar, 10cm²		24 hours	 Agar Stamp  SA	Staphylococcus aureus Count A
Agar Stamp  AC Total Bacteria Count Agar, 10cm² 10pcs/bag; 100pcs/box 48±2 hours 6 months Agar Stamp  EC Coliform group&E.coli Count Agar, 10cm² 24 hours Agar Stamp  SA Staphylococcus aureus Count A Performance Characteristics of Contact Agar Based Medium4x4 ². It's divided into 10 small cells which are easy to count. Microbiology Agar...
Transport Culture Media (for Fecal Collection)
Transport Culture Media (for Fecal Collection) Functional Application of Transport Culture Media: Collecting feces/sample preservation/scale inspection/safety and hygiene Fecal examination is o...
Peristaltic Pump
Peristaltic Pump Peristaltic pump AK-bio AKP001 Used for the separate packing device of the test tube and Petri dish. Performance Characteristics of Peristaltic...
Sterile Sampling Bag (for Liquid)
Sterile Sampling Bag (for Liquid) The Purpose of Sterile Blender Bag(for Liquid) For liquid sample collection Sterilization Method of Sterile Sampling Bag (for Liquid) Gamma-ray rad...
Все товары поставщика

Похожие товары

Electric Motorcycle Manufacturer in China
Electric Motorcycle Manufacturer in China Продавец: IU samrt Co., Ltd (shenzhen) An power scooter motorcycleis also called a motor scooter. As a certified chinese electric motorc...
Octadecanedioic acid
Octadecanedioic acid Продавец: Shanghai Sinoexpo Informa Markets Category:Pharmaceutical Intermediates Product Name:Octadecanedioic acid CAS No.:CAS NO.871-70-5 ...
O-Methylhydroxylamine hydrochloride
O-Methylhydroxylamine hydrochloride Продавец: Shanghai Sinoexpo Informa Markets Category:Pharmaceutical Intermediates Product Name:O-Methylhydroxylamine hydrochloride CAS No.:CA...
3,8,11-Trioxa-5-azatridecan-13-oic acid, 2,2-diMethyl-4-oxo-
3,8,11-Trioxa-5-azatridecan-13-oic acid, 2,2-diMethyl-4-oxo- Продавец: Shanghai Sinoexpo Informa Markets Category:Pharmaceutical Intermediates Product Name:3,8,11-Trioxa-5-azatridecan-13-oic acid, 2,2-d...
Fmoc-L-Lys[Oct-(otBu)-Glu-(otBu)-AEEA-AEEA]-OH
Fmoc-L-Lys[Oct-(otBu)-Glu-(otBu)-AEEA-AEEA]-OH Продавец: Shanghai Sinoexpo Informa Markets Category:Pharmaceutical Intermediates Product Name:Fmoc-L-Lys[Oct-(otBu)-Glu-(otBu)-AEEA-AEEA]-OH...