Violet Red Bile Agar

Violet Red Bile Agar is a medium for the enumeration of coliform organisms in food and dairy products and conforms to the American Public Health Association (APHA).

Yeast extract and enzymatic digest of gelatin provide the required carbon, nitrogen and vitamins. Sodium chloride maintains the osmotic balance. The medium is made selective by the inclusion of bile salts and crystal violet to inhibit Gram-positive and non-enteric organisms.

Lactose is a fermentable carbohydrate and neutral red is a pH indicator. Lactose fermenters produce red/purple colonies often surrounded by a halo of the same colour. Non-lactose fermenters produce pale colonies. Selectivity can be increased by incubation at 42-44C.

 Enumeration of coliform organisms in food and dairy products.

Shelf Life (days): 1095 days

Storage Temp (°C): 10-30°C

Dehydrated Medium Appearance: Fine Powder

Prepared Medium Appearance: Firm Gel

Dehydrated Medium Colour: Beige/light purple

Prepared Medium Colour: Light Purple

Dehydrated PH: 7.4 ± 0.2

Prepared PH: 7.4 ± 0.2

Recommended Incubation: Aerobically at 30°C ± 1°C for 18-24 hours