Columbia 5% Sheep Blood Agar Plate is supplied by HiMedia. It contains 25ml of sterile ready prepared agar in 90mm disposable plates. This red coloured medium has a pH in the range of 7.1 to 7.5. Columbia 5% Sheep Blood Agar is used for isolation and cultivation of fastidious organisms. It is advisable to store this product between 2-8C. Composition (in gm/L) is as follows:

Peptone, special (23.00)

Corn starch (1.00)

Sodium chloride (5.00)

Agar (15.00)

Sheep Blood (5.00)

Columbia Blood Agar Base is a general-purpose nutritious agar base which was formulated by Ellner et al in 1966. It is further enriched by adding sterile blood. Columbia Blood Agar Base w/ 1 % Agar is used as a base for preparing media containing blood and as a selective media formulation in which different combinations of antimicrobial agents are used as additives. Corn starch provides energy and also neutralizes toxic metabolites. Sheep blood permits the detection of haemolysis and also provides heme (X factor) which is required for the growth of many bacteria. However it is devoid of V factor (Nicotinamide adenine dinucleotide) and hence Haemophilus influenzae which needs both the X and V factors, does not grow on this medium. Owing to a relatively high carbohydrate content of this medium, beta-haemolytic Streptococci may exhibit a greenish haemolytic reaction which may be mistaken for the alpha haemolysis. It is advisable to carry out confirmatory tests of all the colonies. Columbia Agar Base with added sterile serum provides an efficient medium for Corynebacterium diphtheriae virulence test medium.