Litmus Lactose Agar 500G

This media was formulated by Wurtz for the differentiation of lactose fermenting and lactose non-fermenting bacteria. Litmus is the pH indicator, which turns red at acidic pH. Colonies of lactose fermenting bacteria are surrounded by a red zone, which distinguishes them from colonies of other organisms that either do not change the surrounding medium or change it to blue, due to the production of ammonia.