2,3,5-Triphenyltetrazolium Chloride (TTC) is a redox indicator. In the TTC assay (also known as TTC test or tetrazolium test), TTC is used to differentiate between metabolically active and inactive tissues or cells. The white compound is enzymatically reduced to red TPF (1,3,5-triphenylformazan) in living tissues or cells due to the activity of various dehydrogenases (enzymes important in oxidation of organic compounds and thus cellular metabolism), while it remains as white TTC in areas of necrosis since these enzymes have been either denatured or degraded. TTC test is a reliable, sensitive, and specific adjunct in the examination of the human heart at necropsy to diagnose acute myocardial infarction in the human population. In addition TTC test may be used for diagnostics of bacteriuria.