Himedia MacConkey Agar w/ CV and w/o NaCl

MacConkey Agar w/ CV w/o NaCl is a differential medium recommended for the selection and recovery of the Enterobacteriaceae and related enteric gram-negative bacilli. Selective agents, Bile salts and crystal violet inhibit most species of gram-positive bacteria. Gram-negative bacteria usually grow well on the medium and are differentiated by their ability to ferment lactose. Lactose-fermenting strains grow as red or pink coloured colonies and may be surrounded by a zone of acid precipitated bile. Escherichia coli and Enterobacter aerogenes ferment lactose while Salmonella species, Shigella species, Staphylococcus aureus does not ferment lactose.