MR-VP MEDIUM

MR-VP Medium is a biochemical test medium used to perform the Methyl Red (MR) and Voges-Proskauer (VP) tests for the identification of enteric Gram-negative bacilli. These supplementary tests are used to distinguish between species of bacteria by detecting the specific end products of carbohydrate metabolism.
The medium contains buffered peptone water providing nutrients for the growth of the micro-organisms and dextrose as an immediate source of carbon. The Methyl Red and Voges-Proskauer reactions can be carried out by adding the respective reagents separately after growth in the medium. The Methyl Red test is used to detect stable acidic end products of mixed-acid fermentation, and the Voges-Proskauer test detects acetoin, a product of an alternative pathway of glucose metabolism.
These reactions together provide some useful biochemical characters for separating members of the coli-aerogenes group from other enteric organisms. Thus the medium provides a common basis for two established biochemical identification tests and enables laboratories to compare different metabolic patterns from the same culture preparation.
The simple formulation and dual-test application of the MR-VP Medium make it useful for routine biochemical characterization and presumptive identification of enteric Gram-negative bacteria.

Enables Methyl Red and Voges-Proskauer testing to differentiate enteric Gram-negative bacilli based on carbohydrate metabolism products.