This Biplate is a combination of XLD Agar + MacConkey Agar W/ 0.15% Bile salts ,CV and NaCl and is recommended for selective isolation and enumeration of Salmonella species and differentiation of enteric pathogens. XLD Agar is a selective agar based on sugar fermentation, lysine decarboxylation and H2S production. H2S producers produce black centred colonies. Sodium deoxycholate inhibits gram positive organisms. MacConkey Agar is a selective agar based on lactose fermentation with neutral red as indicator. Bile salts and crystal violet inhibits gram positive organisms.