Eosin Methylene Blue (EMB), a microbiological media, is a differentiating medium that slightly inhibits the growth and color of Gram-positive bacteria. It also provides a color indicator to distinguish between organisms that ferment lactose (e.g. E.coli) and those who do not (e.g. Salmonella, Shigella). Holt-Harris, Teague, and Levine first created EMB agar.