Iodonitrotetrazolium (INT) is a monotetrazolium salt used as an indicator dye.1,2 It is reduced to an insoluble formazan that is used as a vital dye or indicator of cellular redox activity.1 Reduction commonly results from the activity of dehydrogenases, although non-enzymatic electron transfer reactions can occur in the presence of an intermediate electron acceptor.1,3 INT is commonly used to measure the respiratory activity of microorganisms in a variety of contexts.1,2
1.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) 2.Sabnis, R.W.Handbook of biological dyes and stains: Synthesis and industrial applications(2010) 3.Green, J.D., and Narahara, H.T.Assay of succinate dehydrogenase activity by the tetrazolium method: Evaluation of an improved technique in skeletal muscle fractionsJ. Histochem. Cytochem.28(5)408-412(1980)