Tryptic Soy Agar with Lecithin and Polysorbate 80 (Difco)
Trypticase™ Tryptic Soy Agar with Lecithin, Polysorbate 80 is recommended for the detection and enumeration of microorganisms present on surfaces of sanitary importance.
Principles Casein and soy peptones are a source of nutrients required for the replication of microorganisms. Sodium chloride maintains osmotic equilibrium. Lecithin and polysorbate 80, two commonly used neutralizers, are reported to inactivate residual disinfectants when the sample is being collected. Lecithin is incorporated to neutralize quaternary ammonium compounds and polysorbate 80 is used to neutralize substituted phenolic disinfectants. Agar is the solidifying agent.