Letheen Broth Base (7105)

Intended Use

Letheen Broth Base is expertly formulated to work in conjunction with Tween 80 (Polysorbate 80) for the precise testing of quaternary ammonium compounds to assess their antimicrobial activity.

Product Summary and Explanation

Introduced in 1948, Letheen Broth Base emerged from research by Weber and Black, highlighting the necessity of a highly nutritional medium that features effective neutralizers for quaternary ammonium compounds found in various sanitizers. This medium's unique composition, which integrates Lecithin and Polysorbate 80 into a Tryptone Glucose Extract (TGE) Agar framework, allows it to effectively neutralize quaternary ammonium compounds while simultaneously enabling accurate testing of germicidal activity.

Developed specifically as a subculture medium, Letheen Broth Base is instrumental in neutralizing quaternary ammonium compounds during disinfectant testing. Significant findings from Quisno, Gibby, and Foter revealed that the augmentation of Lecithin and Polysorbate 80 into F.D.A. Broth resulted in a medium that could adequately neutralize high concentrations of quaternary ammonium salts. The resulting product, aptly named "Letheen"—a blend of Lecithin and Tween—proves advantageous with its ease of preparation and clear appearance, facilitating visual inspection for microbial growth.

Letheen Broth Base is acknowledged by the Official Methods of Analysis of the Association of Official Analytical Chemists (AOAC) for use with disinfectants that contain cationic surface active materials. Furthermore, this broth base is specified by the American Society for Testing Materials (ASTM) within the Standard Test Method for Preservatives in Water-Containing Cosmetics. It is vital to ensure total neutralization of disinfectants to avoid false negatives (no-growth) during assessments.