Liofilchem® VP (KOH) Reagent Droppers, 10mL

The Liofilchem™ VP (KOH) Reagent is designed for performing the Voges-Proskauer (VP) test, a qualitative assay used to differentiate members of the Enterobacteriaceae family based on their ability to metabolize glucose and produce acetylmethylcarbinol (acetoin) as a fermentation byproduct. This test aids in bacterial identification, often used in clinical and industrial microbiology.

Key Features

1. Purpose:
   • Differentiates Enterobacteriaceae based on glucose metabolism and acetoin production.
   • Serves as an aid in bacterial identification, requiring additional tests for comprehensive results.
2. Kit Components:
   • 5 vials of Sodium Alpha-naphthol solution (10 mL each)
   • 5 vials of Potassium Hydroxide (KOH) solution (10 mL each)
   • 2 empty dropper bottles for optional reagent transfer.
3. Reagent Specifications:
   • Alpha-Naphthol: 5% (w/v) in ethyl alcohol.
   • KOH Solution: 40% (w/v) in distilled water.
4. Quality and Performance:
   • Validated with quality control (QC) strains to ensure reliable results.
   • Compatible with bacterial identification systems such as the EnteroPluri-Test.
5. Storage and Stability:
   • Store at 2–8°C away from light in the original packaging.
   • Shelf life: 2 years.

Method Principle

Certain bacteria ferment glucose to produce acetoin. When VP reagents are added:

• Acetoin is oxidized to diacetyl, which reacts with creatine (present in the medium) to form a red-colored compound.
• The intensity and color development indicate the result of the test.

Applications

1. Clinical Microbiology:
   • Identification of bacteria causing infections, particularly within the Enterobacteriaceae family.
2. Industrial Microbiology:
   • Quality control and safety testing in food and pharmaceutical industries.
3. Research:
   • Used in metabolic pathway studies for bacterial species.

Test Procedure

Standard Method (Barritt’s Modification):

1. Preparation:
   • Inoculate MR-VP broth with a pure bacterial culture.
   • Incubate at 35 ± 2°C for 24–72 hours.
2. Testing:
   • Transfer 1–2 mL of the broth culture to a clean test tube.
   • Add:
     • 0.6 mL (12 drops) of Sodium Alpha-naphthol solution.
     • 0.2 mL (4 drops) of KOH solution.
   • Mix thoroughly and shake well to expose to atmospheric oxygen.
3. Result Observation:
   • Positive result: Development of a pink to bright red color within 20 minutes.
   • Negative result: No color change or development of a copper color (negative).

Other Methods:

• Compatible with systems like the EnteroPluri-Test.
• Follow the specific manufacturer’s instructions when using VP (KOH) reagent with other systems.

Quality Control

Advantages

• Rapid and Reliable: Provides results within 20 minutes.
• Versatile: Compatible with multiple bacterial identification systems.
• Ease of Use: Dropper bottles simplify reagent application.
• Validated Performance: Meets strict quality control standards.

Limitations

• Allow at least 20 minutes for color development to confirm a negative result.
• Results must be interpreted alongside other diagnostic data for accurate identification.

Storage and Handling

• Store at 2–8°C in its original packaging until the expiry date.
• Protect from light and avoid contamination of reagents.
• Dispose of expired or deteriorated reagents according to local regulations.

Safety and Precautions

1. For in vitro diagnostic use (IVD) only.
2. Ensure proper training and laboratory practices.
3. Handle all samples as potentially infectious.
4. Follow standard laboratory safety protocols.
5. Consult the Safety Data Sheet (SDS) for handling information.

Packaging Information

The Liofilchem™ VP (KOH) Reagent is an indispensable tool for bacterial identification, offering rapid, reliable, and easy-to-use reagents for the Voges-Proskauer test, ensuring diagnostic accuracy in clinical and industrial settings.