(AB) Violet Red Bile Glucose Agar, 500 grams

Violet Red Bile Glucose Agar is recommended for use in the microbiological analysis of food. Violet Red Bile Glucose Agar is a selective medium which detects the growth of glucose fermenting Gram negative bacteria. The glucose fermenting bacteria lower the pH of the medium subsequently causing their colonies to look red (neutral red dye) and to precipitate the bile salts. Crystal violet and bile salts inhibit the growth of Gram positive microorganisms. Agar medium used for the detection and determination of all Enterobacteriaceae in food. (Alpha Biosciences # V22-102-500gm)

Use: Agar medium used for the detection and determination of all Enterobacteriaceae in food.

Description:Violet Red Bile Glucose Agar is recommended for use in the microbiological analysis of food. Violet Red Bile Glucose Agar is a selective medium which detects the growth of glucose fermenting Gram negative bacteria. The glucose fermenting bacteria lower the pH of the medium subsequently causing their colonies to look red (neutral red dye) and to precipitate the bile salts. Crystal violet and bile salts inhibit the growth of Gram positive microorganisms.

Formula* per Liter:

• Pancreatic Digest of Gelatin........... 7.0g
• Glucose ..........................................10.0g
• Yeast Extract .................................... 3.0g
• Sodium Chloride............................. 5.0g
• Bile Salts #3 .................................... 1.5g
• Neutral Red ................................... 0.03g
• Agar .................................................13.5g
• Crystal Violet .............................. 0.002g

Final pH: 7.4 ± 0.2 at 25.0°C

* Grams per liter may be adj. or formula supplemented to obtain desired performance

Preparation: Mix 40 grams of the medium in one Liter of purified water until evenly dispersed. Heat with repeated stirring and boil for two minutes. DO NOT AUTOCLAVE. Cool to 40° to 45°C and dispense 15-20 mL into 100 mm Petri dishes containing inoculum. After solidification of the inoculated medium, evenly add a cover of 4 mL of the cooled (45°- 46.0°C) agar medium.

Quality Control Specifications:

1. The powder is homogeneous, free flowing and light reddish-beige.
2. Visually the prepared medium is clear to slightly hazy and reddish purple.
3. Expected cultural response after 18-24 hours at 35.0°C.

Organism                                                                        Result

Enterobacter aerogenes ATCC 13048                 Growth, Red colonies

Escherichia coli ATCC 25922                               Growth, Red colonies

Salmonella typhimurium ATCC 14028                  Growth, Red colonies

Staphylococcus aureus ATCC 25923                       Growth Inhibited

Storage: Store the sealed bottle containing the dehydrated medium at 2 to 30.0°C. Once opened and recapped, place the container in a low humidity environment at the same storage temperature. Protect it from moisture and light. The dehydrated medium should be discarded if it is not free flowing or if the color has changed from the original light pinkish-beige color.