Deoxycholate Citrate Agar (Agar Medium J) is supplied by Micromaster. It is available in the form of a light yellow to pinkish beige homogeneous free flowing powder which has a pH in the range of 7.1 to 7.5. It is advisable to store this product below 30C.

Quantity provided: 500 g/pack

Deoxycholate Citrate Agar is prepared as per the modified formula of Leifson and is a selective medium recommended for the isolation of enteric pathogens particularly Salmonella species as per Indian Pharmacopoeia. This medium is used for the isolation and maximum recovery of intestinal pathogens belonging to Salmonella and Shigella groups from foods and pharmaceutical products. However, it is recommended to use less inhibitory medium when Shigellae have to be isolated. Sodium deoxycholate at pH 7.3 to 7.5 is inhibitory for gram-positive bacteria. Proteus and other Gram-positive organisms are also inhibited due to higher concentration of both citrate and deoxycholate salts in this medium. The reduction of ferric citrate to iron sulphide by H2S gives the indicative appearance of colonies with black center. Citrate salt, in the concentration included in the formulation, are inhibitory to gram-positive bacteria and most other normal intestinal organisms. Combination of beef extract and meat peptone supplies nitrogen, mineral, vitamin factors required for enhanced growth. Lactose monohydrate supplies fermentable carbohydrate source in this medium. Neutral red acts as indicators, in presence of which lactose fermenters like coliform bacteria give pink colonies while lactose non-fermenters give colourless colonies.