Letheen Agar Base is used to determine the antimicrobial activity of quaternary ammonium compounds. Based on Tryptone Glucose Extract (TGE) Agar, incorporation of Lecithin and Tween 80 results in the efficient neutralization of these compounds in disinfectants while testing germicidal activity. Enzymatic Digest of Casein and Yeast Extract supply amino acids, peptides, carbohydrates, vitamins, and minerals. Sodium Chloride maintains the osmotic balance. Agar is the gelifying agent.