Letheen Broth with Tween, Modified is used for the recovery of microorganisms from cosmetics in a laboratory setting and 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 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 as disinfectant residues can result in a false negative (no-growth) test result.

Letheen Broth with Tween, Modified is based on the formula described in FDA Bacteriological Analytical Manual, and a modification of Letheen Broth Base. This medium is recommended by the FDA for use in the microbiological testing of cosmetics. Letheen Broth with Tween, Modified has Polysorbate 80 (Tween) incorporated into the medium.