2,3,5-Triphenyltetrazolium chloride

Color indicator. Supplement in culture media for the microbiological analysis of food and water samples

TTZ, Tetrazolium Red, TTC, TT, 2,3,5-Triphenyltetrazolium chloride, TPTZ
Empirical Formula (Hill Notation):
CAS Number:
Molecular Weight:
Beilstein/REAXYS Number:
MDL number:

storage conditions

Store at +5°C to +30°C.

Quality Level


≥98% (calculated on dried substance, perchloric acid titration)




microbiology: suitable (preparation)


3.7 (20 °C, 10 g/L in H2O)


243 °C (decomposition)


150 g/L

bulk density

230 kg/m3

storage temp.


SMILES string




InChI key


Looking for similar products? Visit Product Comparison Guide

General description

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.


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

Analysis Note

Assay (perchloric acid titration, calculated on dried substance): ≥ 98 %
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

Certificate of Analysis

Certificate of Origin

Yu-Wen Hung et al.
FASEB journal : official publication of the Federation of American Societies for Experimental Biology, 34(5), 6950-6964 (2020-04-05)
Dipeptidyl peptidase-4 inhibitors (or gliptins), a class of antidiabetic drugs, have recently been shown to have protective actions in the central nervous system. Their cellular and molecular mechanisms responsible for these effects are largely unknown. In the present study, two...
Ilkin Yucel Sengun et al.
Food science and biotechnology, 29(3), 401-408 (2020-04-08)
In the present study, variety of fruit vinegars were investigated in terms of their physicochemical, microbiological and bioactive properties. Total phenolic and flavonoid contents were in the range of 933-1162 mg GAE/L and 66.64-470.86 mg/L in terms of catechin equivalents, respectively. During...

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

Contact Technical Service

Social Media

LinkedIn icon
Twitter icon
Facebook Icon
Instagram Icon


Research. Development. Production.

We are a leading supplier to the global Life Science industry with solutions and services for research, biotechnology development and production, and pharmaceutical drug therapy development and production.

© 2021 Merck KGaA, Darmstadt, Germany and/or its affiliates. All Rights Reserved.

Reproduction of any materials from the site is strictly forbidden without permission.