2. Convenient access: the Petri dish has a large lid and a small bottom. If it is placed directly, it is easy to get only the lid when taking it, resulting in the exposure of the culture medium in the Petri dish, which leads to the pollution of the culture medium or the fall of the Petri dish.
3, easy to observe: the inversion of the Petri dish can control the diffusion of colonies in the Petri dish, which is beneficial to the formation of a single colony and convenient for experimental observation;
4. Avoid pollution: Inversion can prevent the water vapor in the culture dish from condensing on the dish cover and dripping on the culture medium, and introduce miscellaneous bacteria into the culture medium to cause pollution, thus affecting the growth of microorganisms in the culture medium.
5. Convenient collection: Sometimes the purpose of culture is to collect bacterial metabolites. However, some metabolites are easily soluble in water, and distilled water will appear on the cover when the Petri dish is placed, resulting in colonies blocking. Inverted Petri dishes can promote the collection, counting or separation of metabolites.
6. Avoid cracking: In the forced ventilation incubator, the Petri dish can be inverted to reduce the air flow on the surface of the culture medium and the evaporation rate of water in the culture medium, so that the culture medium is not easy to crack.
Extended data:
Matters needing attention in microbial inoculation:
(1) The inoculation room should be kept clean, the countertops and walls should be scrubbed with phenol soap, and fumigated with lactic acid or formaldehyde regularly. Sterilize with ultraviolet lamp before each use. Regularly check the sterility of the inoculation room.
(2) Before entering the inoculation room, personal hygiene should be done well, and work shoes, hat, work clothes and masks should be replaced in the buffer room. Work clothes, work shoes and masks are only allowed to be used in the inoculation room. Don't wear it elsewhere, change it regularly and disinfect it.
(3) Inoculated test tubes, triangular bottles, etc. Should be marked, indicating the name and date of the culture medium and strain. All items moved into the inoculation room must be wiped clean with 70% alcohol in the buffer room.
(4) Disinfect hands with 70% alcohol or bromogeramine before inoculation, and do not leave the flame of alcohol lamp during operation; The tampon is not misplaced; Inoculation tools need flame sterilization before and after use.
(5) Constant temperature incubator should be cleaned and disinfected frequently.
Baidu Encyclopedia-Dilution Inverted Plate Method
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