Tryptone is a general-purpose growth peptone produced by the digestion of casein with the protease trypsin and used as a nitrogen source in culture media formulated for isolating and cultivating fastidious and non-fastidious bacteria, fungi, and some protozoa. It is a refined hydrolysate with high solubility and is used as a microbiological nutrient in laboratory media and fermentations. It is a high-quality source of amino acids and peptides produced by the pancreatic digestion of casein.
Tryptone is recommended for laboratory media and fermentation and has been used in antibiotics, toxins, and enzyme productions. It is also used as a nutrient in vaccine production where a high free amino acid content is required. Tryptone may also be used in STGG (skim milk, tryptone, glucose, glycerol) medium at -80°C, which is used to preserve Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis isolates for at least 3 years.