Introduction of DHL Agar DHL Agar is the short name for Deoxycholate Hydrogen Sulfide Lactose Agar. It is a modification of Deoxycholate Agar and it was proposed by Sakazaki et. al. DHL agar supplies contain a rich nitrogen base to permit the growth of fastidious strains of Salmonella and Shigella species. The colonies formed are considerably larger than those found on similar selective media (MacConkey agar, S-S agar, etc.). Principle of DHL Agar Enzymatic Digest of...
Introduction of Hektoen Enteric Agar Hektoen enteric agar was developed in 1968 by Sylvia King and William I. Metzger in an effort to increase the recovery of Salmonella and Shigella species over the previously formulated Salmonella-Shigella (SS) Agar. This is also known as HEK and HEA. This medium is particularly useful in the isolation of Shigella species. They formulated HE Agar medium while working at the Hektoen Institute in Chicago and became able to increase the...
Introduction of Neomycin Blood Agar Neomycin Blood Agar is a selective medium used for the isolation of group A ( Streptococcus pyogenes) and B streptococci (Streptococcus agalactiae). Composition of Neomycin Blood Agar Typical Formula gm/liter (BBL) Pancreatic Digest of Casein: 14.5 Papaic Digest of Soybean Meal: 5.0 Sodium Chloride: 5.0 Growth Factors: 1.5 Neomycin: 0.03 Sheep Blood defibrinated: 50 ml Agar: 14.0 g Principle of Neomycin Blood Agar The pancreatic Digest of Casein incorporation of medium...