Liofilchem® Sodium Selenite for Bacteriological Use

Liofilchem® Sodium Selenite is a selective chemical reagent used in bacteriological media preparation, particularly as a selective agent in enrichment media for the isolation of Salmonella spp. It is a well-established component in classical microbiological methods for food, environmental, and public health testing.

Sodium selenite exhibits strong inhibitory activity against competing background flora, including many Gram-positive and Gram-negative bacteria, notably enterococci and coliforms, while allowing the preferential growth of salmonellae during enrichment.

Physicochemical Characteristics

• Solubility in Water: Soluble
• Granulometry: ≤ 80 mesh
• Melting Point: 740 °C
• Selenium Content: 45.15 %

Principle of Use

Sodium selenite acts as a selective inhibitory compound in enrichment broths by suppressing competing microorganisms that may otherwise overgrow or mask Salmonella spp. Its selective toxicity enables improved recovery of salmonellae from samples with heavy microbial backgrounds.

The reagent is commonly incorporated into selenite-based enrichment media, where it is dissolved in distilled water and sterilized by autoclaving as part of the medium preparation process.

Applications

• Preparation of Salmonella enrichment media
• Food microbiology testing
• Environmental and public health microbiology
• Quality control laboratories
• Research and reference microbiology laboratories

Quality Control

• Appearance: Homogeneous powder
• Color: White

Storage & Stability

• Storage Temperature: 10–30 °C
• Store in original container, protected from light
• Do not use beyond expiry date or if signs of deterioration or contamination are observed
• Shelf Life: 4 years

Safety & Precautions

• Classified as hazardous under current legislation
• Handle only by trained laboratory personnel
• Consult the Safety Data Sheet (SDS) before use
• Use appropriate personal protective equipment (PPE)

Waste Disposal

Dispose of waste in accordance with national and local regulations governing hazardous chemical materials.

Packaging & Ordering Information

References

1. American Journal of Hygiene, 24:423, 1936
2. Public Health Reports, 63:1075, 1916

Liofilchem® Sodium Selenite is a classical, reliable selective agent essential for the preparation of Salmonella enrichment media. Its proven inhibitory properties against competing flora and long-standing use in bacteriological methods make it a critical reagent for food safety, environmental, and public health microbiology laboratories.