IRON AGAR 500 grams/bottle

Iron Agar (Lyngby) is used for the enumeration of H2S producing bacteria. Bacteriological peptone provides nitrogen, vitamins, minerals and amino acids essential for growth. Yeast extract is a source of vitamins, particularly of the B-group. Sodium chloride supplies essential electrolytes for transport and osmotic balance. Sodium thiosulfate is reduced to hydrogen sulfide, which reacts with the iron salt to give the black iron sulfide. L-Cysteine is added to detect the production of H2S of bacteria that do not produce hydrogen sulfide from thiosulfate but only from the sulphur containing amino acid. Bacteriological agar is the solidifying agent. Bacteria capable of forming H2S from either source of sulphur would appear as black colonies.