A Petri dish (alternatively known as a Petri plate or cell-culture dish) is a shallow transparent lidded dish that biologists use to hold growth medium in which cells can be cultured, originally, cells of bacteria, fungi and small mosses.
The container is named after its inventor, German bacteriologist Julius Richard Petri. It is the most common type of culture plate. The Petri dish is one of the most common items in biology laboratories and has entered popular culture. The term is often written in lower case, especially in non-technical literature.
Penicillin, the first antibiotic, was discovered in 1929 when Alexander Fleming noticed that mold that had contaminated a bacterial culture in a Petri dish had killed the bacteria all around it.
The Petri dishes were what I needed.