010Bichotomous Blood Agar – Mac Conkey Agar No2 plate is used for the culture of aerobic gram(+) cocci and gram(-) bacteria from clinical samples. For the culture, isolation, and identification of enterobacteria and enterococci. Streak the plates using the isolated colony technique. Incubate for 24 hours under aerobic conditions at 35 – 37º C. The morphology of the colonies after incubation is as follows: On Blood Agar: Hemolytic streptococcus gives transparent or matte colonies, grey in color, surrounded by a zone of beta-hemolysis. Pneumococcus exhibits flat transparent colonies surrounded by a small zone of green alpha-hemolysis. Staphylococcus exhibits matte, white to golden-yellow colonies with or without a zone of beta-hemolysis. On Mac Conkey Agar No2: Enterococcus grows in 36 – 48 hours and will show small intensely red colonies with a lighter colored periphery, approximately 1mm in diameter. Non-lactose fermenting bacteria appear colorless.