Description
Blood Agar Base, Veg / with low pH, Veg is prepared by using Veg hydrolysate No.1 and Veg infusion, thus making the media free of BSE/TSE risks. These media are used as a base for preparation of blood agar. Blood Agar Base, Veg / with low pH, Veg are highly nutritious media and can also be used as a general purpose growth media without adding blood. If the culture medium base is to be used without blood, the pH should be adjusted to 7.2 to 7.4 since most bacteria can grow better in a slightly alkaline medium. The pH value of 6.8 stabilizes the red blood corpuscles and favours the formation of clear zone of haemolysis and is advantageous for cultivation of Streptococci and Pneumococci. These media like the conventional media can be used with added phenolphthalein phosphate for the detection of phosphatase producing Staphylococci, with added salt and agar for assessment of surface contamination on equipment and pig carcasses and to determine salinity range of marine flavobacteria. It can be used for preparation of S. serotype Typhi antigens. This medium can be further enriched with added serum or blood. With added blood it is suitable for detection of typical haemolytic reactions. However, haemolytic reactions depend on the animal blood used. Sheep blood gives best results for Group A Streptococci. When horse blood is used, Haemophilus haemolyticus colonies produce haemolysis and mimic Streptococcus pyogenes.
