MacConkey Agar – Selective & Differential Microbiology Medium

MacConkey Agar is a selective and differential microbiological culture medium commonly used for the isolation and differentiation of appropriate Gram-negative enteric bacteria. Its selective components inhibit many Gram-positive organisms, while the differential system allows organisms to be differentiated based on lactose fermentation. Typical formulations contain lactose and the pH indicator neutral red; lactose-fermenting colonies generally develop pink-to-red coloration, while non-lactose fermenters typically remain relatively colourless or pale.