Side 1: Columbia Agar with 5% Horse Blood
This is a general-purpose medium enriched with 5% defibrinated horse blood that is suitable for the isolation of most organisms, including many fastidious anaerobes.
Side 2: Columbia Agar with 5% Horse Blood and CAP Selective Supplement
This is a medium for the selective isolation of Staphylococcus spp. and Streptococcus spp. primarily from clinical specimens. Based on Columbia Agar Base enriched with 5% horse blood the medium is made selective by the inclusion of colistin and aztreonam to suppress the growth of the majority of Gram-negative bacteria.