Table 18.3 Tetrazolium salts for detecting redox potential in living cells and tissues.

Cat No. Tetrazolium Salt Color of
of Formazan
M6494 (MTT) 3-(4,5-Dimethylthiazol-2-yl)-2,
5-diphenyltetrazolium bromide
purple no
  • Superoxide generation by fumarate reductase ref and nitric oxide synthase ref
  • Mitochondrial dehydrogenase activity ref
  • Cell viability and proliferation ref
  • Neuronal cell death ref
  • Platelet activation ref
  • Tumor cell adhesion ref and invasion ref
  • Multidrug resistance ref
  • In vitro toxicity testing ref
N6495 (NBT) Nitro blue tetrazolium chloride deep blue no
  • Superoxide generation by xanthine oxidase ref
  • Neutrophil oxidative metabolism ref
  • NADPH diaphorase activity ref
  • Succinic dehydrogenase histochemistry ref
X6493 (XTT) 2,3-Bis-(2-methoxy-4-nitro-5-sulfophenyl)
orange yes
  • Antifungal susceptibility ref
  • Drug sensitivity of cells ref
  • Parasitic nematode viability ref
  • Tumor cell cytotoxicity ref