TTC is a redox indicator used to detect cellular respiration.1 It is primarily reduced by Complex I in mitochondria and, under anaerobic conditions, is completely reduced to an insoluble red 1,3,5-triphenylformazan.2 TTC assays are typically used as a mitochondrial redox potential indicator for cell death.1
1.Sabnis, R.W.Handbook of biological dyes and stains: Synthesis and industrial applications(2010) 2.Berridge, M.V., Tan, A.S., and Herst, P.M.Tetrazolium dyes as tools in cell biology: New insights into their cellular reductionBiotechnol. Ann. Rev.11127-152(2005)