Chlorure de 2,3,5-triphénytétrazolium, Color indicator. Supplement in culture media for the microbiological analysis of food and water samples

2,3,5-triphenyltetrazolium chloride (TTC) is an indicator recommended for the microbiological analysis of food.

2,3,5-triphenyltetrazolium chloride (TTC) is a dye largely used for enumeration of microbial colonies in solid culture media, being a key component of the dry rehydratable film system used for microbiological analysis of food. This dye is colorless in the oxidized form and red when reduced by microorganisms, due to formation of formazan. Live microorganisms reduce TTC by enzymatic action, forming red color formazan that is kept inside granules in the cells.

Assay : ≥98% (calculated on dried substance, perchloric acid titration)
Form : solid
pH : 3.7 (20°C, 10 g/L in H₂O)
mp = 243°C (decomposition)
Solubility : 150 g/L
Bulk density : 230 kg/m³
Application(s): microbiology
Storage temperature : 2-30°C

Identity (UV/VIS-Spectrum): passes test
Absorption maximum λmax. (water): 245 - 248 nm
Spec. Absorptivity A 1%/1cm (λmax; 0,01 g/l; water; calculated on dried substance): ≥ 770
TLC-Test: passes test
Loss on drying (70 °C; ≤ 1 hPa): ≤ 0.5 %
Suitability for testing the germinability of seeds: passes test
Suitability for microbiology: passes test