Tryptone is an enzymatic digest of casein for use in preparing microbiological culture media in a laboratory setting. Tryptone is not intended for use in the diagnosis of disease or other conditions in humans.

Tryptone is an enzymatic digest of casein used as a nitrogen source in culture media. Casein is the main protein of milk, and a rich source of amino-acid nitrogen. Tryptone is rich in tryptophane, making it valuable for use in detecting indole production. The absence of detectable levels of carbohydrates in Tryptone makes it a suitable peptone in differentiating bacteria on the basis of their ability to ferment various carbohydrates.

Several media containing Tryptone are specified in standard methods for multiple applications.