MacConkey Broth EP/USP, Syrup

A medium recommended by the Harmonized USP/EP/JP for the selective enrichment of Escherichia coli
from non-sterile samples. Conforms to Harmonized USP/EP/JP performance specification. Gelatin
peptone provides a source of nitrogen, while lactose is a fermentable carbohydrate. Ox bile acts a
selective agent inhibiting most Gram-positive organisms and bromocresol purple acts as a pH indicator. A
color change from purple to yellow indicates growth of a bile tolerant, lactose fermenting organism such
as Escherichia coli. According to the Harmonized USP/EP/JP, MacConkey Broth is used as a selective
enrichment broth, with subculture performed onto MacConkey Agar.