Lauryl Sulfate Tryptose Broth (LST)

Lauryl Sulfate Tryptose Broth (LST) is a vital microbiological medium designed for detecting and enumerating coliforms in water, dairy products, and foods. It specifically targets E. coli, making it crucial for food safety testing and water quality analysis. By providing an optimal environment for coliform growth, LST ensures accurate results.

Key Features:

• High Sensitivity: LST promotes rapid growth of coliform bacteria, even from minimal inoculum sizes. This makes it ideal for effective E. coli testing.
• Inhibition of Competing Organisms: Sodium lauryl sulfate suppresses non-coliform bacteria, allowing for clear identification of coliforms in various samples.
• Balanced Nutritional Support: The broth includes pancreatic digest of casein and lactose, supplying essential nutrients for robust bacterial growth.
• Stable pH: With a final pH of 6.8±0.2, the potassium phosphate buffering system maintains an optimal environment for microbial development.

Usage Instructions:

To prepare Lauryl Sulfate Tryptose Broth, dissolve 35.6g of the dehydrated medium in one liter of deionized water. Mix well and heat gently until fully dissolved. Dispense the mixture into test tubes fitted with Durham gas-collecting tubes. Then, autoclave at 121°C for 15 minutes. For inoculum sizes of 1 ml or less, use single strength; for 10 ml or more, choose double strength.

Appearance:

The dehydrated medium appears as a free-flowing yellowish powder. In contrast, the prepared broth is a clear, yellowish liquid, reflecting its high purity and quality.

Storage and Shelf Life:

Store Lauryl Sulfate Tryptose Broth tightly capped in its original container at temperatures between 5-30°C. The dehydrated medium has a shelf life of three years from the manufacturing date. Keep the prepared medium at 2-8°C, away from direct light.

Quality Control:

For optimal results, prepare the medium according to the label instructions. Incubate at 36±1°C for 24-48 hours to ensure reliable coliform testing. This aligns with best practices in microbiological testing.