Detect and enumerate Enterobacteriaceae in food, animal feed, and environmental samples with this selective medium.
Selectively enumerate Enterobacteriaceae in food, animal feed, and environmental samples with Thermo Scientific™ Oxoid™ Violet Red Bile Glucose (VRBG) Agar (ISO). Formulated with selective inhibitory components — neutral red, crystal violet, and bile salts — VRBG Agar suppresses non-target Gram-positive bacteria while promoting recovery of Enterobacteriaceae. Use VRBG Agar for examination of samples for indicator groups such as coliforms and total Enterobacteriaceae to assess food hygiene, quality, and spoilage potential.
Key Benefits
- Easy-to-read results: Enterobacteriaceae form purple–pink colonies due to the neutral red indicator and crystal violet.
- Glucose-based formulation (Mossel modification) improves recovery of Enterobacteriaceae compared with lactose media.
- Produces characteristic purple halos of precipitated bile salts around colonies.
- Useful indicator of process failure, under-processing, or post-processing contamination in processed foods.
- Tested for performance against ISO 21528 and ISO 11133:2014 standards.
Background
Originally described by Mossel and later modified by Mossel & Cowell, VRBG Agar (a glucose-modified form of Mossel VRBL) takes advantage of rapid glucose fermentation by Enterobacteriaceae to produce distinctive coloured colonies and bile-salt precipitation, while crystal violet and bile salts inhibit Gram-positive organisms.
Specifications
- Content and Storage: 10°C to 30°C
- Form: Powder
- Quantity: 500 g
- Standards: ISO 21528; ISO 11133:2014