GranuCult® prime MacConkey (MAC) Agar is a selective agar medium that is designed for the isolation and confirmation of Escherichia coli and other Enterobacteriaceae, e.g. Salmonella and Shigella, from the food chain, cosmetic, pharmaceutical and other materials. This culture medium contains crystal violet and bile salts that inhibit the growth of the Gram-positive microbial flora whilst it allows the Gram-negative bacteria to grow. Peptones provide nitrogen, vitamins and amino acids. Lactose and the pH indicator neutral red are used to detect lactose degradation. The fermentation of lactose is causing a local drop down of the pH, resulting in a colour change of the pH indicator neutral red. By this, reddish-pink colonies are formed and the medium around the colonies changes its colour to reddish. Often a bile precipitation zone around the colony is formed. Bile salts and crystal violet inhibits the growth of Gram-positive bacteria. Agar is the solidifying agent.

GranuCult® prime MacConkey (MAC) agar is used to isolate and to confirm Escherichia coli and other Enterobacteriaceae, e.g. Salmonella and Shigella, from the food chain, cosmetic, pharmaceutical and other materials.A variety of bacteria like salmonella spp, shigella spp and coliform bacteria from samples.