Description
5-
Cyano-
2,3-
di-
(
p-tolyl)tetrazolium (chloride) is a redox-
sensitive tetrazolium salt used primarily to detect metabolic activity in microorganisms. This membrane-
permeable indicator is readily taken up by living cells and reduced by respiratory activity to produce a red fluorescent, water-
insoluble formazan crystal (absorption maximum at 450 nm). While the oxidized salt is non-
fluorescent, the reduced formazan can be evaluated using a standard rhodamine filter set (excitation: 510-
560 nm; emission > 590 nm), although optimum excitation requires a blue 420 nm excitation filter. For flow cytometry, a 480 nm excitation laser combined with detection in the red region is suitable.
Uses
5-Cyano-2,3-di-p-tolyltetrazolium Chloride is a monotetrazolium redox dye that is used as a vital stain for actively respiring bacteria. Redox dye producing a fluorescent formazan (only in solid state) upon reduction; used as cellular indicator of respiratory activity in cells.
