modified Tryptic Soy Agar- Dehydrated Culture Media

NutriSelect^® prime Tryptic Soy Agar halal with Lecithin and Polysorbate 80 acc. EP, USP, JP, EN 17141 and ISO 21149 is used for enumeration and detection of aerobic mesophilic microorganisms (Total aerobic microbial count) present in cosmetics, pharmaceutical and other products containing preservatives and for determining the sanitation efficiency of containers, equipment, and work area (environmental monitoring).

The combination of the two peptones, enzymatic digest of casein and of soybean provides a high nutrition by supplying organic nitrogen, amino acids, and longer-chained peptides. In this complex medium the osmotic balance is supplied by sodium chloride whilst agar-agar is the solidifying agent.
This modification of Tryptic Soy Agar contains lecithin and polysorbate 80 (also known as Tween^® 80) to inactivate residual disinfectants when sampling. EP, JP, USP, EN 17141 and EN ISO 21249 recommend incorporating lecithin to neutralize quaternary ammonium compounds (QACs), para-hydroxybenzoates (parabens) and bis-biguanides and to add polysorbate 80 to neutralize QACs, iodine and parabens. Polysorbate 80 is reported as well for neutralizing phenols, hexachlorophene, and formalin.
Tryptic Soy Agar (TSA) with Lecithin and Polysorbate 80 can be used to prepare plates for different usage, e.g. contact plates for surface-sampling, plates for surface-plating and air-sampling techniques, for membrane filtration and for pour-plating technique.

NutriSelect is a registered trademark of Merck KGaA, Darmstadt, Germany

TWEEN is a registered trademark of Croda International PLC