VRB (VIOLET RED BILE LACTOSE) AGAR (C15-1295-720)

General description

GranuCult^® prime VRB (Violet Red Bile Lactose) agar is used for the detection and colony counting of coliform bacteria. Crystal violet and bile salts inhibit the growth of the Gram-positive accompanying bacterial flora. Degradation of lactose to acid is indicated by the pH indicator neutral red, which changes its color to red, and by precipitation of bile acids. The enzymatic digest of animal tissue provides carbon and nitrogen sources for bacterial growth. Yeast extract primarily supplies the B-complex vitamins, while agar is the solidifying agent.

Application

GranuCult^® prime Violet Red Bile Lactose (VBRL) agar is suitable for the detection and colony counting of coliform bacteria from food and animal feed, water, and other materials.

Features and Benefits

• GranuCultgr^® 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
• Granulation technology allowS many supplements to be included, with no need to add these separately

Linkage

Replaces: 1014065007

Analysis Note

Appearance (clearness): clear
Appearance (colour): 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.
Inoculum on reference medium (Escherichia coli ATCC 8739 (WDCM 00012)):
Colony count (Escherichia coli ATCC 8739 (WDCM 00012)):
Recovery on test medium (Escherichia coli ATCC 8739 (WDCM 00012)): ≥ 50 %
Colony colour (Escherichia coli ATCC 8739 (WDCM 00012)): purplish-red colonies with or without precipitate halo
Inoculum on reference medium (Escherichia coli ATCC 25922 (WDCM 00013)):
Colony count (Escherichia coli ATCC 25922 (WDCM 00013)):
Recovery on test medium (Escherichia coli ATCC 25922 (WDCM 00013)): ≥ 50 %
Colony colour (Escherichia coli ATCC 25922 (WDCM 00013)): purplish-red colonies with or without precipitate halo
Inoculum on reference medium (Enterobacter cloacae ATCC 13047 (WDCM 00083)):
Colony count (Enterobacter cloacae ATCC 13047 (WDCM 00083)):
Recovery on test medium (Enterobacter cloacae ATCC 13047 (WDCM 00083)): ≥ 50 %
Colony colour (Enterobacter cloacae ATCC 13047 (WDCM 00083)): purplish-red colonies with or without precipitate halo
Growth (Pseudomonas aeruginosa ATCC 27853 (WDCM 00025)): no limit
Colony colour (Pseudomonas aeruginosa ATCC 27853 (WDCM 00025)): colourless to beige colonies
Growth (Enterococcus faecalis ATCC 19433 (WDCM 00009)): total inhibition
Growth (Enterococcus faecalis ATCC 29212 (WDCM 00087)): total inhibition
Incubation: 24 ± 2 hours at 30 ± 1 °C
Reference media: Tryptic Soy Agar
A recovery rate of 50 % is equivalent to a productivity value of 0.5.
The indicated colony counts result from the sum of a triple determination.

Other Notes

• The prepared medium is clear and red
• If the medium is to be used immediately for the poured plate technique, cool it to 44-47 °C in a water bath before use
• If the medium is used for the surface plating technique, there should be no visible moisture on the plates before use
• The prepared plates can be stored at 2 °C to 8 °C in the dark and protected against evaporation for up to 5 days

Footnote

We offer two media types: the superior granulated GranuCult^® and the cost-efficient powdered NutriSelect^® culture media, depending on your needs.
The designations basic, plus, or prime are added to indicate the quality control level, from basic quality control to standard QC plus to prime for full regulatory compliance.

Legal Information

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

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