VRB AGAR

General description

Fluorocult^® VRB-MUG Agar is a selective medium for the detection and enumeration of coliform bacteria, in particular E. coli. Meat peptone provides amino acids and other complex nitrogenous substances, and yeast extract supplies Vitamin B complexes. Lactose is a fermentable carbohydrate. Crystal violet and bile salts inhibit the growth of accompanying Gram-positive bacterial flora. Neutral red acts as a pH indicator. Lactose-positive colonies show a color change to red due to acid production. Lactose-negative Enterobacteriaceae are colorless. Lactose-positive colonies are red and often surrounded by a turbid zone due to the precipitation of bile acids. E. coli colonies appear fluorescent under UV light. β-D-glucuronidase, which is produced by E. coli, cleaves 4-methylumbelliferyl-β-D-glucuronide (MUG) to 4-methylumbelliferone and glucuronide. The fluorogenic 4-methylumbelliferone can be detected under a long-wavelength UV lamp.

Application

Fluorocult^® VRB Agar is suitable for the detection and enumeration of coliform bacteria, particularly E. coli, in food and dairy products.

Features and Benefits

• Fluorocult^® fluorogenic culture media offer Rapid and Reliable culture testing
• Powerful alternatives to conventional microbiological methods for the rapid and sensitive detection of bacteria
• Offers superior granulated culture media
• Safe and sustainable due to reduced risks associated with fine dust and toxic substance inhalation, resulting in a safer work environment
• Excellent wettability, solubility, and free-flowing properties
• Convenient, with minimal component separation and clumping, even under warm or humid conditions
• High batch-to-batch reproducibility
• Prolonged shelf life of up to five years
• High number of test strains exceeding all regulatory demands

Analysis Note

Appearance (clearness): clear
Appearance (color): dark red
pH-value (25 °C): 7.2 - 7.6
Solidification behaviour (2 hrs., 45 °C): liquid
Growth promotion test in accordance with the current version of DIN EN ISO 11133.

Growth(Escherichia coli ATCC 8739 (WDCM 00012)): good to very good
Growth Escherichia coliATCC 25922 (WDCM 00013): good to very good
Growth (Pseudomonas aeruginosa ATCC 27853 (WDCM 00025)): no limit
Growth (Enterococcus faecalis ATCC 19433 (WDCM 00009)): total inhibition
Growth (Enterococcus faecalis ATCC 29212 (WDCM 00087)): total inhibition
Colonies (Escherichia coli ATCC 8739 (WDCM 00012)): red with precipitation halo
Colonies (Escherichia coli ATCC 25922 (WDCM 00013)): red with precipitation halo
Colonies (Pseudomonas aeruginosa ATCC 27853 (WDCM 00025)): colourless to beige
Fluorescence (Escherichia coli ATCC 8739 (WDCM 00012)): + (poor)
Fluorescence (Escherichia coli ATCC 25922 (WDCM 00013)): +
Fluorescence (Pseudomonas aeruginosa ATCC 27853 (WDCM 00025)): + (greenish)
Incubation: 18 - 24 hours at 35 °C aerobic.

Legal Information

FLUOROCULT is a registered trademark of Merck KGaA, Darmstadt, Germany