Soyabean Casein Digest Agar Plate with 1% Glycerol & 4% Polysorbate 80 (Gamma irradiated) is supplied by HiMedia. It contains sterile ready prepared media in 55mm scored polystryrene plates. This light-yellow coloured medium has a pH in the range of 7.1 to 7.5. Soyabean Casein Digest Agar is commonly used for the subculture of aerobic organisms. It is advisable to store this product between 15-25C. Composition (in gm/L) is as follows:

Pancreatic digest of casein (15.00)

Papaic digest of soybean (soyabean) (5.00)

Sodium chloride (5.00)

Agar (15.00)

Various pharmacopoeias recommend Soybean Casein Digest Agar as sterility testing medium. It is also used in validation of sterility checking procedure in accordance with the microbial limit testing harmonized methodology of USP/EP/BP/JP. This medium is used in microbial limit test and antimicrobial preservative - effective test. Gunn et al used this medium for the growth of fastidious organisms and study of haemolytic reaction after addition of 5% v/v blood. The combination of pancreatic digest of casein and papaic digest of soybean meal makes these media nutritious by providing amino acids and long chain peptides for the growth of microorganisms. Natural sugars of soya enhance growth of microorganism. Sodium chloride maintains the osmotic balance in the medium. Agar is the solidifying agent. The total aerobic count is considered to be equal to the number of colonies forming units found on this medium, if colonies of fungi are detected on this medium they are counted along with total aerobic count.