metallic green sheen characteristic colonies of escherichia coli on eosin methylene blue aar emb in close up

agar analysis background bacteria biology biomedical biotech biotechnology blue closeup coli coliform colony culture dish disk emb enteric eosin escherichia fecal ferment food gram green growth hand identification indicator isolated isolation lab laboratory media metallic methylene microbial microbiology negative pathogen pathogenic petri plate positive research sample science scientist selective water