High grade Salmonella Shigella Agar is supplied by Micromaster. It is available in the form of a light yellow to pink homogenous free flowing powder with a pH in the range of 6.8 to 7.2. It is advisable to store this product below 30C.

• Quantity provided: 500 g/pack

Salmonella Shigella Agar (SS Agar) is a differential selective media used for the isolation of Salmonella and some Shigella species from pathological specimens, suspected foodstuffs etc. Agar is a moderately selective medium in which gram-positive bacteria are inhibited by bile salts, brilliant green and sodium citrate. Proteose peptone and beef extract supply the essential growth nutrients. Lactose is the fermentable carbohydrate. Brilliant green, bile salts and thiosulphate selectively inhibit gram-positive and coliform organisms. Sodium thiosulphate is reduced by certain species of enteric organisms to sulphite and H2S gas and this reductive enzyme process is attributed by thiosulphate reductase. Production of H2S gas is detected as an insoluble black precipitate of ferrous sulphide, formed upon reaction of H2S with ferric ions or ferric citrate, indicated in the centre of the colonies. The high selectivity of Salmonella Shigella Agar allows the use of large inocula directly from faeces, rectal swabs or other materials suspected of containing pathogenic enteric bacilli. On fermentation of lactose by few lactose-fermenting normal intestinal flora, acid is produced which is indicated by change of colour from yellow to red by the pH indicator-neutral red. Lactose non-fermenting organisms grow as translucent colourless colonies with or without black centres.