Levine's Eosin Methylene Blue (EMB)
Purpose: To isolate and differentiate between various members of
the family Enterobacteriaceae.
Principle: EMB is an undefined selective/differential medium.
It contains aniline dyes (methylene blue and eosin), which inhibit the
growth of Gram-positive bacteria selecting for Gram-negative bacteria.
EMB also contains lactose which makes the media differential based on an
organisms ability to ferment lactose.
The characteristic green-gold
sheen observed by a heavy-lactose fermenting bacteria on Levine's EMB
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