Columbia Blood Agar Base is a solid medium used for the cultivation of fastidious and non-fastidious microorganisms. The enriched medium is usually prepared with horse, sheep, or rabbit blood to determine the hemolytic reactions of fastidious pathogenic microorganisms. This medium contains a highly nutritious combination of peptones. The addition of Starch enhances the recovery of Neisseria, and the hemolytic reaction of some Streptococci. Enzymatic Digest of Casein, Meat Peptone, and Yeast Enriched Peptone provide nitrogenous sources, vitamins, and minerals. Potato Starch is the carbon source. Sodium Chloride maintains the osmotic equilibrium. Agar is the gelifying agent.