For isolation, cultivation and detection of haemolytic activity of Streptococci, Pneumococci and other fastidious microorganisms. BLOOD AGAR BASE NO. 2 medium is used for the isolation, cultivation and detection of hemolytic activity of Streptococci, Pneumococci and other fastidious microorganisms. The Blood Base No. 2 medium contain highly nutritious extract ( Liver extract & Yeast extracts ) these extracts provide vitamins, carbohydrates, salts and other organic nitrogen compounds. Sodium chloride provides essential ions and maintains electrolyte balance. Proteose peptone provides additional growth factors in the medium. Agar is a solidifying agent. Supplementation with blood (5-10%) provides additional use in isolation, cultivation, and determination of hemolytic reactions, of fastidious pathogenic microorganisms.Hemolytic patterns may vary with the source of animal blood or type of base medium used showed none of the hemolytic activity with good growth pattern of culture after incubation period of 48 hours. By using sheep blood, V factor destroying enzyme ( nucleotidase ) which prevents the growth of emophilus species on sheep blood agar unless another microorganisms, eg., Staphylococci, provides the V factors. Small amounts of reducing sugars inhibit the expression of β-hemolytic, and β -hemolytic Streptococci may develop a green zone or ring of hemolysis.