Hektoen Enteric Agar is supplied by Micromaster. It is available in the form of a cream to yellow with tancast homogeneous free flowing powder which has a pH in the range of 7.3 to 7.7. It is advisable to store this product below 30C.

Quantity provided: 500 g/pack

Hektoen Enteric Agar, a selective and differential medium designed to isolate and differentiate members of the species Salmonella and Shigella from other Enterobacteriaceae, was developed by King and Metzger. When compared to other selective medium, this medium inhibits the growth of Salmonella and Shigella very slightly; thus, giving high yields of these microorganisms, but at the same time inhibits accompanying gram-positive microorganisms. Bile salts, bromthymol blue and acid fuchsin inhibit the growth of most gram-positive organisms. Lactose, salicin and sucrose, serves as fermentable source of carbohydrates to encourage the growth and differentiation of enteric bacteria. By increasing the carbohydrate and peptone content in Hektoen Enteric Agar, the inhibitory effect of bile salts and indicators are countered. Proteose peptone provides nitrogen, carbon, and amino acids required for organism growth. Yeast Extract is a vitamin source. Sodium chloride maintains the osmotic balance of the medium. Sodium thiosulfate provides a source of sulfur. Hektoen Enteric Agar can also detect the production of hydrogen sulfide gas, which turns parts of the medium black. Ferric ammonium citrate serves as iron source, which cause production of hydrogen sulfide from sodium thiosulphate and also aids in the visualization of hydrogen sulfide production by reacting with hydrogen sulfide gas to form a black precipitate.