What are the selective agents for emb agar?

The selective agents in EMB (Eosin Methylene Blue) agar are the dyes eosin Y and methylene blue. These dyes inhibit the growth of Gram-positive bacteria while allowing Gram-negative bacteria to grow. Additionally, the medium differentiates between lactose fermenters, which produce acid and may appear purple or metallic green, and non-lactose fermenters, which remain colorless. This makes EMB agar useful for isolating and identifying enteric Gram-negative bacteria.