Letheen Broth Base Modified without Tween is used with Polysorbate 80 for the recovery of microorganisms from cosmetics in a laboratory setting. Letheen Broth Base Modified without Tween is not intended for use in the diagnosis of disease or other conditions in humans.

In 1948, Weber and Black described the value of a highly nutritional solid medium containing neutralising agents for quaternary ammonium compounds in sanitisers. The addition of Lecithin and Polysorbate 80 to Tryptone Glucose Extract (TGE) Agar resulted in a medium that effectively neutralises quaternary ammonium compounds in testing of germicidal activity. Total neutralisation of disinfectants is critical. Disinfectant residues can result in a false negative (no-growth) test.

Letheen Broth Base Modified without Tween is based on the formula described in FDA Bacteriological Analytical Manual, and a modification of Letheen Broth Base. Letheen Broth Base Modified is recommended by the FDA for use in the microbiological testing of cosmetics.

• Analyte: non-selective
• Platform: dehydrated culture media
• Formula: Letheen broth base 20.7g/L, enzymatic digest of casein 5.0g/L, enzymatic digest of animal tissue 10.0g/L, yeast extract 2.0g/L, sodium bisulfite 0.1g/L
• Grams per litre: 37.80
• Litres per 500g: 13.00