MacCONKEY AGAR PLATE (W/ 0.15% BILE SALTS, CV and NaCl )

MacConkey Agar Plate (W/ 0.15% Bile Salts, CV And NaCl) is the widely used selective and differential medium for isolation of gram negative enteric bacteria from clinical, food, water, dairy, pharmaceutical and industrial samples. Its selectivity for the recovery of Enterobacteriaceae and its ability to be used to differentiate lactose fermenters at the same time, makes it an extremely useful medium for the routine testing of microbiology. It is also recommended by USP for Microbial Limit Tests and is widely accepted by APHA for the examination of water and food samples.
What makes this medium especially valuable is its clear visual differentiation of bacterial colonies. Pink to red colonies, possibly surrounded by a zone of precipitated bile, are formed by organisms that ferment lactose, for example, Escherichia coli, producing acid during fermentation. In contrast, non-lactose fermenters like Salmonella and Shigella are colourless and transparent, which allows for easy differentiation on culture. Pancreatic digest of gelatin, peptic digest of animal tissue and casein enzymic hydrolysate provide the vital nutrients while lactose is the fermentable carbohydrate. Neutral red functions as the pH indicator, and bile salts with crystal violet suppress Gram-positive organisms, ensuring selective growth of Gram-negative bacteria.

Selective and differential culture medium for isolating Gram-negative enteric bacteria and differentiating lactose fermenting coliforms.