This HiDip slide is recommended for microbial screening of food and water. PCA: Plate Count Agar : Recommended for determination of plate counts of microorganisms in food, water, waste water & clinical . Also called as Standard Methods Agar. It is recommended by APHA and FDA for determination of counts. VRBA :This medium is recommended for selective isolation, detection and enumeration of coli-aerogenes bacteria in water, milk other dairy food products and clinical . It is based on lactose fermentation with neutral red as the indicator. Bile salts and crystal violet inhibits gram positive bacteria. It can be used for selective isolation of Enterobacteriaceae.