Description: Blood agar, which is used for the cultivation of bacteria. To use it, you must open it in a clean area wearing gloves. The plate should dry in the incubator at 37°C, for about 30 – 45 minutes. Then inoculate the plates with the sample to be examined, as soon as possible after taking it from the laboratory, in a way that allows isolated colonies to grow. In case some pathogenic microorganisms require carbon dioxide for their initial isolation, the plates should be incubated in an atmosphere containing 5-10% CO2, at 35-37°C for 18-24 hours. The morphology of the colonies after incubation is as follows: Hemolytic streptococcus gives transparent matte colonies, grey in color, surrounded by a zone of beta-hemolysis. Pneumococcus exhibits flat transparent colonies surrounded by a small zone of green beta-hemolysis. Staphylococcus exhibits matte, white to golden-yellow colonies with or without a zone of beta-hemolysis.