Eosin-Methylene Blue Agar (EMB)

Eosin-Methylene Blue (EMB) Agar is a lactose-containing medium with eosin and methylene blue dyes for isolating Gram-negative enteric bacteria. Formulation A (GF1052F dehydrated, KL1052F granulated) is stated for the isolation of Gram-negative enteric bacteria, especially coliforms and fecal coliforms; it is prepared at 37.5 g per litre with a final pH of 7.1±0.2.

Formulation B (GF645F) is described as a weakly selective medium for isolating enteric pathogens, particularly Escherichia coli. It adds beef extract and sodium chloride, uses methylene blue at 0.1 g/L, is prepared at 42.5 g per litre with a final pH of 7.2±0.2 and is stored at 2-25 °C. Both formulations are sterilized at 121 °C for 15 minutes and have a 3-year sealed shelf life.