BLOOD AGAR BASE Nº 2 (ISO 7932) 500 grams/bottle

Blood Agar Base  Nº 2 is a base medium rich in nutritional properties, used for the preparation of blood agar plates. It is used for the isolation, cultivation and recovery of fastidious microorganisms to study hemolysis activity. Liver extract and yeast extract provide nitrogen, vitamins, minerals and amino acids essential for growth. Sodium chloride maintains the osmotic equilibrium. The blood is an additional source that provides growth factors for the microorganisms and is the basis for determining hemolytic reactions. Hemolytic patterns may vary with the type of blood or base medium used. For example, defibrinated sheep blood gives best results for Group A streptococci. Bacteriological agar is the solidifying agent. This medium can be used to prepare a selective medium for Brucella spp or Campylobacter spp by adding an antibiotic supplement. It may also be used for the primary isolation of Haemophilus spp. This medium has been recommended by ISO normative 7932 for the confirmation of Bacillus cereus. The Bacillus cereus has positive reaction of ß-hemolysis. The width of the hemolysis zone may vary. It is also a medium recommended by ISO normative 11290-1 for the confirmation of Listeria monocytogenes. . A zone of ß- hemolysis is considered a positive reaction. Results: 1. Alpha-hemolysis: greenish discoloration of medium. 2. Beta-hemolysis: clear zone surrounding colony. 3. Gamma-hemolysis: no change.