Description

TCBS Agar: The Ultimate Medium for Vibrios Isolation

TCBS Agar is a specialized culture medium designed for the selective isolation of Vibrios from various clinical specimens, water, and food sources. Its unique formulation promotes the growth of Vibrio species while inhibiting unwanted bacteria, making it an essential tool in microbiology labs.

Key Ingredients and Their Functions

The composition of TCBS Agar includes:

• Yeast Extract (5.0 g/L): Provides essential nutrients that support bacterial growth.
• Sodium Chloride (10.0 g/L): Maintains osmotic balance, crucial for Vibrio survival.
• Proteose Peptone (10.0 g/L): Supplies amino acids and peptides necessary for protein synthesis.
• Ferric Ammonium Citrate (1.0 g/L): Serves as an indicator for hydrogen sulfide production.
• Sodium Thiosulfate (10.0 g/L): Acts as a sulfur source that enhances the detection of H2S.
• Bromothymol Blue (0.04 g/L) and Thymol Blue (0.04 g/L): These pH indicators help visualize metabolic activity through color changes.
• Sodium Citrate (10.0 g/L): Aids in buffering the medium.
• Oxgall (8.0 g/L): Inhibits gram-positive bacteria, promoting the growth of Vibrios.
• Saccharose (20.0 g/L): A fermentable carbohydrate that supports the metabolism of Vibrios.
• Agar (15.0 g/L): Provides a solid surface for colony formation.

The final pH of TCBS Agar is 8.6±0.2 at 25℃, which is optimal for recovering Vibrio cholerae and other related species.

Preparation and Usage

To prepare TCBS Agar, suspend 89.0 g of the medium in one liter of distilled or deionized water. After heating with frequent agitation and boiling for one minute, cool the mixture to 45-50℃ before pouring it into Petri dishes. Important Note: Do not autoclave this medium, as it can alter its selective properties.

Appearance and Storage

The dehydrated TCBS Agar appears as a free-flowing light grey granule, while the prepared medium forms a visually appealing blue-green gel. For optimal performance, store the dehydrated medium tightly capped in its original container at temperatures between 5-30°C. It boasts a shelf life of three years from the manufacturing date. Once prepared, the medium can be stored out of direct light at 2-8°C.

Quality Control and Testing

For effective quality control, inoculate the TCBS Agar and incubate it at 36±1℃ for 18-24 hours. Observing the growth of typical Vibrio colonies will confirm the medium’s efficacy.

Conclusion

When it comes to isolating Vibrios from diverse samples, TCBS Agar stands out due to its selective formulation and ease of use. By incorporating essential nutrients and inhibitors, this medium facilitates accurate identification and analysis of Vibrio species, including those relevant in clinical and environmental studies. Whether you’re working in a research lab or a clinical setting, TCBS Agar is your go-to solution for efficient and reliable Vibrio isolation.