Petri cup - type of glassware that is widely used in bacteriological practice for growing bacteria on solid nutrient media. Petri dish consists of two flat transparent glass plates, one of which with a larger diameter, serves as a lid. The most commonly used Petri dish of 10 cm diameter, 1.5 cm height. Before using petri dishes thoroughly washed with tap water or soda soap and a brush, then rinsed with distilled water and sterilized with dry heat. Before sterilization, the petri dish is folded into a metal foam or wrapped in paper.
In a sterile Petri dish pour 25-30 ml of t ° then cooled to 55 ° of melted medium at a strictly horizontal surface. Bacterial colonies were counted, looking for a cup of light.