Neogen® Letheen Agar Base Modified without Tween

Letheen Agar Base Modified (without Tween) is used with Tween 80 (Polysorbate 80) for the isolation of microorganisms from cosmetics in a laboratory setting. Letheen Agar Base Modified 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 neutralizing agents for quaternary ammonium compounds in sanitizers. The addition of Lecithin and Tween 80 (Polysorbate 80) to Tryptone Glucose Extract (TGE) Agar resulted in a medium that effectively neutralizes quaternary ammonium compounds in testing of germicidal activity. Total neutralization of disinfectants is critical. Disinfectant residues can result in a false negative (no-growth) test.

Letheen Agar Base Modified is based on the formula described in FDA Bacteriological Analytical Manual, and a modification of Letheen Agar Base. Letheen Agar Base Modified is recommended by the FDA for use in the microbiological testing of cosmetics.