EMB AGAR or EOSIN METHYLENE BLUE AGAR is used for isolation and differentiation of gram negative enteric bacilli from clinical and non clinical samples. Primarily this medium was used for the detection and confirmation of coliforms. Medium contains Lactose and Sucrose, due to these carbohydrates sources medium can be differential in primary culture: salmonellas and shigellas which are lactose-negative can be differentiated from other lactose- negative but sucrose-positive organisms such as Proteus sp. Peptone is the nitrogen source in EMB Agar. Agar is a solidifying agent. Dipotassium phosphate is the buffer. Eosin Y and Methylene Blue are the indicators. Methylene blue is also a selective agent.