BLOODAGARBASE (INFUSIONAGAR)W/O BLOOD

Blood agar base (infusion agar) is used for isolation, cultivation of fastidious pathogenic microorganisms after addition of blood. This media can be used as general purpose media also, without blood addition. Blood agar base medium can also be used for primary isolation of Haemophilus species, where defibrinated sheep blood is used to enrich the medium. On addition of blood the pH value of 6.8 stabilizes and favours the formation of clear hemolysis zones. Fresh, defibrinated sheep blood is most suitable for determent hemolysis forms. It gives best results for Group A Streptococci. But sheep blood fails to support growth of Haemophilus haemolyticus due to deficiency of pyridine nucleotides. However, addition of horse blood supports H. haemolyticus growth and haemolysis and the growing colonies mimic Streptococcus pyogenes.

for selective isolation of fastidious pathogenic microorganisms after addition of blood