Medium 7. MacConkey Broth 500G

Recommended as a selective broth for coliforms in accordance with Indian Pharmacopoiea, Bromo cresol purple is the pH indicator in the medium. Lactose fermenting organisms gives yellow colour to the medium due to drop in pH as a result of lactose fermentation, Lactose non-fermenting organisms like Salmonella and Shigella do not alter the appearance of the medium. Gas produced gets entrapped in inverted Durhams tube