A petri dish is a laboratory consumable for microbial or cell culture, which consists of a disc-shaped bottom and a lid. The bottom of the dish is small, the lid is large, and the bottom is used for culture. The materials of the petri dish are basically divided into two categories, mainly plastic and glass. The glass petri dish can be used for plant material, microbial culture and adherent culture of animal cells. Plastic petri dishes can be made of polyethylene material, single-use, suitable for laboratory inoculation, streaking and bacterial isolation operations, and can be used for the cultivation of plant materials.

 

When cleaning petri dishes, petri dishes usually go through four steps of soaking, brushing, pickling and rinsing. We mainly explain glass petri dishes here. Glass dishes should be soaked in clean water to soften and dissolve attachments. New glass dishes should be used before use. It must be scrubbed briefly with tap water, then soaked in 5% hydrochloric acid overnight. Used glass petri dishes are usually accompanied by a large amount of protein and oil, and are not easy to scrub after drying, so they should be immersed in clean water for scrubbing immediately after use.

 

Put the soaked glass petri dish into detergent water, then scrub repeatedly with a soft brush, do not leave dead corners, so as not to damage the surface finish of the tableware, wash the clean glass petri dish, dry it, and then prepare for pickling.

 

Pickling is to immerse the above-mentioned utensils in a cleaning solution, which is also called an acid solution, which removes substances that may remain on the surface of the utensils through the strong oxidation of the acid solution. The pickling time should be no less than six hours, usually overnight or longer.

 

The petri dish after scrubbing and pickling must be fully rinsed with water. Whether the petri dish is cleaned after pickling directly affects the success or failure of cell culture. To wash soaked utensils by hand, each utensil must be "emptied" repeatedly at least 15 times, and finally immersed in distilled water 2-3 times, dried or packaged for later use.

 

The petri dish should be cleaned and sterilized before use, because whether the petri dish is clean or not has a great influence on the experimental work, which may affect the pH value of the medium. If there are certain chemicals, it will inhibit the growth of bacteria. Newly purchased petri dishes should be rinsed with water first, and then soaked in a 1% or 2% hydrochloric acid solution for several hours to remove free alkaline substances, Then rinse twice with distilled water. When culturing bacteria, please use high pressure steam (usually 6.8*10 of the 5th power of Pa high pressure steam), sterilize at 120℃ for 30 minutes, dry at room temperature or sterilize with dry heat, that is, put the petri dish In the oven, the temperature is controlled at about 120°C for 2 hours, which kills the cytotus of the bacteria.