High grade MacConkey Agar is supplied by Micromaster. It is available in the form of a light yellow to pink homogenous free flowing powder with pH in the range of 6.9 to 7.3. For maximum efficiency, it must be stored below 30C in tightly closed container.

Quantity provided: 500g /pack

MacConkey Agar, also referred to as Agar Medium H, is recommended for selective isolation of Escherichia coli from pharmaceutical products. It is also recommended for selective isolation and differentiation of lactose fermenting and non-fermenting enteric bacteria. Pancreatic digest of gelatin and peptones (meat and casein) provide the essential nutrients, vitamins and nitrogenous factors required for growth of microorganisms. Lactose monohydrate is the fermentable source of carbohydrate. The selective action of this medium is attributed to crystal violet and bile salts, which are inhibitory to most species of gram-positive bacteria. Sodium chloride maintains the osmotic balance in the medium. After enrichment of Escherichia coli in MacConkey Broth (M083B), it is then subcultured on MacConkey Agar. Gramnegative bacteria usually grow well on the medium and are differentiated by their ability to ferment lactose. Lactose fermenting strains grow as red or pink and may be surrounded by a zone of acid precipitated bile. The red colour is due to production of acid from lactose, absorption of neutral red and a subsequent colour change of the dye when the pH of medium falls below 6.8. Lactose non-fermenting strains, such as Shigella and Salmonella are colourless and transparent and typically do not alter appearance of the medium.