a shallow, flat‐bottomed, circular dish, usually of glass or transparent plastic and 5–15 cm in diameter, with a loosely fitting, overlapping cover. It is used especially for plate cultures of bacteria and moulds on solid (gelled) media, and for tissue culture.
Steriilsele Petri tassile kantakse kuni temperatuurini 55 °C kuumutatud inokuleeritud söödet. Petri tassile peab moodustuma 0,6–0,8 mm paksune kiht. Petri tassile sisediameetriga 140 mm kulub ligikaudu 15 ml söödet.
By using a small spoon or a spatula one half of the decanted impurities is transferred to a small Petri dish or a microscopic slide for microscopic identification of a possible content of animal constituents (meat fibres, feathers, bone fragments, …).