This is a general-purpose complex medium for the cultivation and isolation of aerobic and anaerobic microorganisms. The base medium, Tryptone Soya Agar (Soybean-Casein Digest agar), conforms to the Harmonized United States Pharmacopoeia (USP), European Pharmacopoeia (EP), and Japanese Pharmacopoeia (JP). The medium can be incubated under aerobic or anaerobic conditions after use for sterility testing, air sampling and other areas of bacteriological investigation.