Lactobacilli MRS Broth is used for the cultivation of lactobacilli and is not intended for use in the diagnosis of disease or other conditions in humans.

Lactobacilli MRS broth was originally developed in 1960 by de Man, Rogosa & Sharpe, the medium can be used for confirmatory tests on organisms isolated on MRS Agar. The medium can also be used for enumeration by the Miles and Misra technique.

Nutrition is provided by a mixture of carefully selected peptones, glucose, beef and yeast extracts while Tween^® 80, magnesium and manganese sulfates act as growth stimulants. Selectivity against streptococci & molds is provided by ammonium citrate and sodium acetate.

Occasionally, sterilization of this medium at 121°C for 15 minutes, in some autoclaves, may cause the pH to fall outside of the specified pH limits 6.4 +/- 0.2. In these rare cases, adjustment of the medium using acetic acid or sodium hydroxide is recommended.