This is a selective medium primarily for the isolation and differentiation of coliforms and non-lactose fermenting Gram –ve bacterial species from clinical, dairy, industrial and water samples. This media differs from the original MacConkey formulation with the addition of an extra 0.5% Sodium chloride, an altered Bile salt mix and the neutral red concentration was also modified. This enhanced the effect of inhibiting Gram +ve and other non-enteric bacterial species. This medium conforms to the requirements of the Harmonised USP/EP/JP.