Description
Columbia Agar with 5% sheep blood is a general all-purpose enriched primary isolation medium that allows growth of all clinically significant anaerobes and facultative anaerobes.
It is recommended when processing clinical specimens for unusual organisms, and is utilized as the base for media containing blood and for selective media formulations in which various combinations of antimicrobial agents are used as additives.
Columbia Agar with 5% sheep blood derives its superior growth-supporting properties from the combination of two peptones, and yeast extract as a supplier of the B complex vitamins.
Corn starch is included to absorb toxic by-products contained in the specimen and serves as an energy source for organisms possessing alphaamylases. Sheep blood allows detection of hemolytic reactions and supplies the X factor (heme) necessary for the growth of many pathogenic species.
- Colonies tend to be larger and growth is more luxuriant than on media containing other blood agar bases
- Recommended as a primary isolation medium in the MiQ standards and in other diagnostic manuals
- In many European countries, this medium has become the most frequently used primary isolation medium for clinical specimens
- Good cultural response to Streptococcus pyogenes 19615, Streptococcus pneumoniae 6305, Staphylococcus aureus 25923 and Escherichia coli 25922
- pH (25°C): 7.3 ± 0.2