Lauryl Tryptose Broth (2X) w/MUG, DT

Perform fluorogenic assays to detect Escherichia coli in water, wastewater, and foods using Thermo Scientific™ Remel™ Lauryl Tryptose Broth with MUG. E. coli produces an enzyme β-glucuronidase that hydrolyzes MUG (4-methylumbelliferyl- β-glucuronide) which is a fluorogenic compound. Only E. coli and some strains of Salmonella and Shigella produce β-glucuronidase. Lauryl Tryptose Broth with MUG is recommended by the American Public Health Association, AOAC International (AOAC) and the U.S. Food and Drug Administration^1-3.

Mallman and Darby developed Lauryl Tryptose Broth^4,5 and they determined that addition of sodium lauryl sulfate to selective media produced the best results for the detection of the coliform groups in water and wastewater. Feng and Hartman incorporated MUG into Lauryl Tryptose Broth to help in detection of E. coli⁶. A fluorescent end-product may be detected in the broth under exposure to long ultraviolet light wave after 4-24 hours incubation.

• Recommended by the American Public Health Association, AOAC International (AOAC) and the U.S. Food and Drug Administration^1-3
• Selective medium - Selective agent sodium lauryl sulfate inhibits many organisms other than coliforms
• Turbidity in the broth and gas bubbles in the inverted Durham tube indicates positive fermentation reaction
• β-glucuronidase hydrolyzes MUG to yield a fluorescent end-product 4-methylumbelliferone
• Easy to interpret -
  • Positive test - Turbidity with gas production as a result of lactose fermentation is a presumptive evidence of the presence of coliforms. Blue fluorescence within 48 hours is evidence of E. coli.
  • Negative test - Turbidity with no gas production and no fluorescence within 48 hours

This medium contains casein peptone that supplies nitrogen, carbon, and sulfur required for the bacterial growth. Sodium chloride provides essential electrolytes and maintains osmotic equilibrium. Lactose is the carbohydrate source fermented by coliforms. Dipotassium phosphate and monopotassium phosphate present in the medium serve as buffering agents.