ttc can be converted to insoluble red formazan by the activity of
Tetrazolium chloride In the TTC assay (also known as TTC test or tetrazolium test), TTC is used to differentiate between metabolically active and inactive tissues. The white compound is enzymatically reduced to red TPF (1,3,5-triphenylformazan) in living tissues due to the activity of various dehydrogenases (enzymes important in oxidation of organic compounds and thus cellular metabolism), while it remains in its unreacted state in areas of necrosis since these enzymes have either denatured or degraded.
Tetraethyllead In most industrialized countries, a phaseout of TEL from road vehicle fuels was completed by the early 2000s because of concerns over air and soil lead levels and the accumulative neurotoxicity of lead. The use of catalytic converters, mandated in the US for 1975 and newer model-year cars to meet tighter emissions regulations, started a gradual phase-out of leaded gasoline in the US.[18] The need for TEL was lessened by several advances in automotive engineering and petroleum chemistry. Safer methods for making higher-octane blending stocks such as reformate and iso-octane reduced the need to rely on TEL, as did other antiknock additives of varying toxicity including metallic compounds such as methylcyclopentadienyl manganese tricarbonyl (MMT) as well as oxygenates including methyl tert-butyl ether (MTBE), tert-amyl methyl ether (TAME), and ethyl tert-butyl ether (ETBE).