VRBA- Composition, Principle, Preparation, Results, Uses

Violet Red Bile Agar (VRBA)

Coliforms refer to all aerobic and facultative anaerobic, gram-negative, non-spore-forming rod-shaped bacteria that ferment lactose with gas and acid formation within 48 hours at 35°C. Procedures to detect, enumerate, and presumptively identify coliforms are used in testing foods and dairy products. One method for performing the presumptive test for coliforms uses Violet Red Bile Agar (VRBA). Violet Red Bile Agar (VRBA) is a selective medium used to detect and enumerate lactose-fermenting coliform microorganisms. Composition of Violet Red Bile Agar (VRBA) … Read more

Water Quality Analysis by Most Probable Number (MPN)

Water Quality Analysis by Most Probable Number (MPN)

The most probable number (MPN) analysis is a statistical method based on the random dispersion of microorganisms per volume in a given sample. In this method, measured volumes of water are added to a series of tubes containing a liquid indicator growth medium. The media receiving one or more indicator bacteria show growth and a characteristic color change. The color change is absent in those receiving only an inoculum of water without indicator bacteria. From the number and distribution of … Read more