Violet Red Bile Agar

//Violet Red Bile Agar

Violet Red Bile Agar

SKU: KM0065 Category:

Violet Red Bile Agar is a medium for the enumeration of coliform organisms in food and dairy products and conforms to American Public Health Association (APHA).
Yeast extract and enzymatic digest of gelatin provides 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 42-44ºC.


Additional Information

Shelf Life (days)

Storage Temp (°C)

Dehydrated Medium Appearance

Prepared Medium Appearance

Dehydrated Medium Colour

Prepared Medium Colour

Dehydrated PH

Prepared PH

Product Description

Organisms Ref. No Result
Escherichia coli ATCC 25922 Growth, red/purple colonies with red precipitate
Salmonella typhmurium ATCC 14028 Growth, colourless colonies
Enterococcus faecalis ATCC 29212 Inhibited



Yeast extract 3.0
Enzymatic digest of gelatin 7.0
Sodium chloride 5.0
Bile salts 1.5
Lactose 10.0
Neutral red 0.03
Crystal violet 0.002
Agar 12.0
Total 38.5
*Adjusted/supplemented as required to meet performance requirements


Suspend 38.5g of the medium in one litre of deionised / purified water. Allow the medium to soak whilst mixing for 10 minutes. Sterilise by boiling for 2 minutes with frequent stirring to completely dissolve the medium. Cool to 45-50°C and aseptically dispense into appropriate sterile containers.