TSC AGAR BASE (As per ISO) is used for detection and enumeration of Clostridium perfringens. Medium consists of Tryptose, Peptic digest of soyabean meal and Yeast extract as source of nitrogenous compounds, carbon, sulphur, vitamin B complex and trace elements essential for Clostridial growth. Sodium metabisulphite and Ferric ammonium citrate act as an indicator of sulphite reduction, indicated by black coloured colonies. S.F.P supplement (TS 0054) or T.S.C supplement (TS 076) help in the selective isolation of C. Perfringens by inhibiting accompanying flora. These antibiotics can also be added to the sterile, liquefied culture medium in the form of filter-sterilized solutions. Egg yolk emulsion serves as a source of lecithin utilized by C. Perfringens. No lecithinase activity can be detected without egg yolk but not all Clostridium perfringens strains show an opaque zone after overnight incubation. So both black lecithinase-positive and black lecithinase-negative colonies should be considered as presumptive Clostridium perfringens on TSC Agar Base and need further confirmatory tests like nitrate reduction, lactose fermentation, gelatin liquefaction and the absence of motility.