A Petri dish (sometimes spelled "Petrie dish" and alternatively known as a Petri plate or cell-culture dish), named after the German bacteriologist Julius Richard Petri, is a shallow cylindrical glass or plastic lidded dish that biologists use to culture cells – such as bacteria – or small mosses. Modern Petri dishes usually feature rings and/or slots on their lids and bases so that when stacked, they are less prone to sliding off one another. Multiple dishes can also be incorporated into one plastic container to create a "multi-well plate". While glass Petri dishes may be reused after sterilization (via an autoclave or one hour's dry-heating in a hot-air oven at 160 °C, for example), plastic Petri dishes are often disposed of after experiments where cultures might contaminate each other.