TRYPTONE YEAST SODIUM SULPHITE AGAR BASE (ISO 14189:2013)

Description

Tryptose Sulphite Cycloserine Agar (TSC) was originally formulated by Harmon et al for the enumeration of C. perfringens from food. TSC Agar has been documented as one of the most useful media for the quantitative recovery of C. perfringens while suppressing growth of other facultative anaerobes. Perfringens Agar Base is also recommended by APHA. Tryptone Yeast Sodium sulphite Agar Base has been recommended by the ISO Committee for the isolation of C.perfringens from water samples using membrane filtration technique. D-Cycloserine help in the selective isolation of C.perfringens by inhibiting accompanying flora. The water sample to be tested is filtered through 0.45 micron filter membrane and the membrane filter is then placed on Tryptone Yeast Sodium sulphite Agar Base and incubated anaerobically at 43-45?C for 18-24 hours. Sulfite reacts with ferric salt to produce sulfide which results in production of black or grey to yellow brown colonies. Confirmatory test: Smear some growth of 24 hours old culture of Clostridium perfringens from Blood Agar /Columbia Agar Base/ Tryptone Soya Agar (incubated anaerobically at 34-38?C) on the filter paper. Add 2-3 drops of Acid phosphatase Reagent on to the colonies of filter paper, observe for appearance of strong purplish colour developed within 3-4 min which is positive reaction for Clostridium perfringens.