Liofilchem™ Tetrathionate Broth Base

The Liofilchem™ Tetrathionate Broth Base is a highly selective enrichment medium used for the isolation of Salmonella typhi and other salmonellae from feces, sewage, and other samples. It complies with the U.S. Pharmacopeia standards and effectively inhibits competing flora, enhancing the recovery of Salmonella spp..

Key Features

1. Selective Enrichment:
   • Combines thiosulfate and tetrathionate to suppress coliform organisms, promoting the growth of Salmonella and Proteus spp.
2. Validated for Clinical and Food Microbiology:
   • Conforms to U.S. Pharmacopeia standards for salmonella isolation.
3. Customizable Selectivity:
   • Proteus spp. inhibition can be enhanced by adding 40 µg/mL novobiocin.

Typical Formula (g/L)

Applications

1. Clinical Microbiology:
   • Enrichment and isolation of Salmonella spp. from fecal and sewage samples.
2. Food Microbiology:
   • Detection of Salmonella in food products.
3. Environmental Testing:
   • Monitoring contamination in water and environmental samples.

Preparation Instructions

1. Prepare Base Medium:
   • Suspend 46.0 g of Tetrathionate Broth Base powder in 980 mL of distilled or deionized water.
   • Heat and stir until fully dissolved.
2. Add Iodine Solution:
   • Cool to below 45°C and aseptically add 20 mL of Iodine Supplement (Code 81009).
   • Mix thoroughly.
3. Dispense and Use:
   • Dispense 10 mL volumes into sterile tubes and use the complete medium on the day of preparation.

Interpretation of Results

• Inoculate the broth with 1-2 g of the sample, mix thoroughly, and incubate at 36 ± 1°C for 18-24 hours.
• Subculture on a selective medium for Salmonella isolation.

Quality Control

• Dehydrated Medium:
  • Appearance: Free-flowing, homogeneous, white to off-white, may have a slight greenish tint.
• Prepared Medium:
  • Appearance: Supernatant over a heavy white precipitate.
  • Color: Nearly colorless to yellow.

Storage and Shelf Life

• Storage:
  • Dehydrated powder: 10–30°C in a dry environment, tightly sealed.
  • Prepared tubes (without iodine): 2–8°C.
  • Add iodine solution at the time of use to the required medium quantity.
• Shelf Life:
  • Valid until the expiry date indicated on the label.

Advantages

• Highly Selective:
  • Suppresses coliforms while promoting Salmonella growth.
• Validated Performance:
  • Tested with quality control strains for reliability.
• Customizable:
  • Optional novobiocin addition enhances selectivity against Proteus spp.
• Cost-Effective:
  • Suitable for large-scale testing with consistent results.

Warnings and Precautions

1. For in vitro diagnostic use (IVD) only.
2. Handle all microbiological specimens as potentially infectious.
3. Dispose of unused or expired product according to local regulations.

Packaging

References

1. The United States Pharmacopeia XXI (1985). Microbial Limit Tests. Rockville, Md.
2. American Public Health Association (1980). Standard methods for the examination of water and wastewater. 15th ed.

Why Choose Liofilchem Tetrathionate Broth Base?

• Proven Selectivity: Ideal for isolating Salmonella spp. in diverse sample types.
• Flexible Application: Effective for clinical, food, and environmental microbiology.
• Validated Performance: Reliable and compliant with global standards.