Violet Red Bile Glucose Agar (VRBG Agar) Plates – Ready-to-Use Selective Culture Medium
Product Overview
Violet Red Bile Glucose Agar (VRBG Agar) Plates are ready-to-use selective and differential culture media designed for the selective isolation of bile-tolerant Gram-negative bacteria in laboratory microbiological testing.
The medium contains yeast extract, gelatin peptone, glucose, sodium chloride, bile salts, neutral red, crystal violet, and agar. Its formulation combines nutritional components with selective agents and a pH indicator to support the growth assessment of target microorganisms under appropriate laboratory conditions.
Supplied as pre-poured agar plates, this product offers a convenient alternative to preparing solid culture media from dehydrated ingredients.
Each plate has a standard diameter of 90 mm and contains approximately 20–25 mL of prepared medium. The product is supplied in triple-layer packaging, with 10 plates per pack.
Key Product Features
- Ready-to-Use Format: Pre-prepared agar plates for convenient laboratory applications.
- Selective Medium: Formulated for the selective isolation of bile-tolerant Gram-negative bacteria.
- Differential Components: Contains glucose and neutral red as part of the medium formulation.
- Defined Composition: Includes yeast extract, gelatin peptone, glucose, bile salts, and other essential ingredients.
- Standard Plate Size: 90 mm diameter.
- Consistent Filling Volume: Approximately 20–25 mL per plate.
- Triple-Layer Packaging: Supplied in triple-layer packaging for product protection.
- Convenient Pack Size: 10 prepared agar plates per pack.
Intended Use
Violet Red Bile Glucose Agar is intended for the selective isolation of bile-tolerant Gram-negative bacteria in laboratory microbiological testing.
The medium can be used for laboratory growth and performance evaluation of relevant bacterial groups, including organisms such as:
- Escherichia coli
- Citrobacter freundii
- Enterobacter aerogenes
The product is intended for professional laboratory use and should be used in accordance with validated laboratory procedures and applicable biosafety requirements.
For microbiological testing only. Not intended for clinical diagnosis or therapeutic use.
Product Specifications
| Parameter | Specification |
|---|---|
| Product Name | Violet Red Bile Glucose Agar |
| Abbreviation | VRBG Agar |
| Medium Type | Selective and Differential Agar |
| Physical Form | Ready-to-Use Prepared Agar Plates |
| Plate Diameter | 90 mm |
| Medium Volume | 20–25 mL per plate |
| Packaging Quantity | 10 plates per pack |
| Packaging Type | Triple-Layer Vacuum Packaging |
| Appearance | Red |
| Initial pH Specification | 7.4 ± 0.2 at 25°C |
| Gel Strength | 500–650 g/cm² |
| Storage Temperature | 2–8°C |
| Storage Conditions | Protect from light |
| Shelf Life | 30 days |
| Intended Application | Selective isolation of bile-tolerant Gram-negative bacteria |
| Product Use | Laboratory Microbiological Testing |
Medium Composition
The formulation contains the following ingredients:
| Ingredient | Amount |
|---|---|
| Yeast Extract | 3.0 g |
| Gelatin Pancreatic Digest (Gelatin Peptone) | 7.0 g |
| Glucose | 10.0 g |
| Sodium Chloride | 5.0 g |
| Sodium Deoxycholate | 1.5 g |
| Neutral Red | 0.03 g |
| Crystal Violet | 0.002 g |
| Agar | 15.0 g |
| Final pH | 7.4 ± 0.2 at 25°C |
The ingredient quantities are stated according to the supplied formulation. Please refer to the manufacturer’s technical documentation for the complete preparation and batch-specific specifications.
Quality Control and Performance Specifications
The prepared agar plates are evaluated according to the following quality requirements:
1. Appearance
The medium should have a red appearance, with a smooth and even surface. No cracks, visible foreign particles, or bubbles should be present.
2. Physicochemical Properties
- pH: 7.4 ± 0.2 at 25°C.
- Gel strength: 500–650 g/cm².
3. Sterility and Moisture Retention
Under the specified quality control conditions:
- Incubation temperature: 30–35°C.
- Incubation duration: 2 days.
- Sterility: No microbial growth should be observed.
- Moisture retention: No significant moisture loss or drying of the medium should occur.
4. Growth Performance
The following performance characteristics are specified by the manufacturer:
- Escherichia coli: Typical colony characteristics and good growth.
- Citrobacter freundii: Typical colony characteristics and good growth.
- Enterobacter aerogenes: Typical colony characteristics and good growth.
- Staphylococcus aureus: Growth inhibition.
Actual growth and colony characteristics may vary depending on the bacterial strain, inoculum, and laboratory testing conditions.
Directions for Use
- Remove the agar plates from refrigerated storage.
- Allow the plates to reach room temperature before use.
- Perform inoculation or microbiological testing according to the applicable laboratory procedure.
- After inoculation, remove the plates from the clean working area and incubate them in an inverted position under the temperature and time conditions specified by the validated test method.
- Observe and record the microbial growth and relevant colony characteristics.
Use appropriate aseptic techniques and laboratory biosafety procedures throughout the testing process.
Storage and Shelf Life
- Storage Temperature: 2–8°C.
- Protect from direct light.
- Recommended Shelf Life: 30 days.
- Keep the product in its original packaging until use.
- Avoid excessive temperature fluctuations during storage and handling.
After opening, any unused plates should be promptly resealed and returned to refrigerated storage to minimize drying and potential contamination.
Condensation may occur if the plates are stored for extended periods or exposed to significant temperature differences. If excessive condensation is present, remove the excess liquid in a clean environment and allow the medium surface to dry under appropriate controlled laboratory conditions before use.
Do not use plates that show visible contamination, cracks, or significant drying.
Important Precautions
- The product is prepared using a boiling-based sterilization process followed by aseptic filling, according to the manufacturer’s production description.
- Inspect the plates before use. Do not use plates that are cracked, excessively dried, or visibly contaminated.
- After opening the package, promptly reseal unused plates and store them at 2–8°C.
- If excessive condensation occurs, handle the plates in a clean environment and allow the surface to dry appropriately before use.
- This product is intended for single use only.
- After use, decontaminate the plates by autoclaving or another validated method, where applicable, and dispose of them according to local biological waste regulations.
- Use this product for laboratory microbiological testing only.
- This product is not intended for clinical diagnosis, therapeutic use, or direct human or veterinary use.
Packaging Information
- Product: Violet Red Bile Glucose Agar (VRBG Agar) Plates
- Plate Diameter: 90 mm
- Medium Volume: 20–25 mL per plate
- Quantity: 10 plates per pack
- Packaging: Triple-layer packaging
- Storage: 2–8°C, protected from light
- Shelf Life: 30 days
Frequently Asked Questions
Q1: What is Violet Red Bile Glucose Agar used for?
Violet Red Bile Glucose Agar is a selective and differential culture medium intended for the isolation of bile-tolerant Gram-negative bacteria in microbiological testing.
Q2: What does VRBG stand for?
VRBG stands for Violet Red Bile Glucose, referring to the selective agar medium formulation.
Q3: Is this product supplied as dehydrated powder?
No. This product is supplied as ready-to-use, pre-poured agar plates.
Q4: What is the size of each plate?
Each plate has a diameter of 90 mm and contains approximately 20–25 mL of prepared medium.
Q5: How many plates are included in one pack?
Each pack contains 10 prepared agar plates.
Q6: How should the product be stored?
Store at 2–8°C and protect from light. Keep unused plates properly sealed and refrigerated.
Q7: What is the shelf life?
The stated shelf life is 30 days. Please check the manufacturing date and expiration date on the product label.
Q8: Is this product suitable for clinical diagnosis?
No. It is intended for laboratory microbiological testing only and is not intended for clinical diagnosis.
Product Notice
Product specifications, composition, and performance characteristics are based on the manufacturer’s supplied product information. Actual performance may depend on the microorganism strain and testing conditions.
Please refer to the product label and accompanying technical documentation for batch-specific information.
For professional laboratory use only. Not intended for clinical diagnosis.
