MTT/MTS Assay

The MTT assay, introduced by Tatsuro Mosmann in 1983, is a colorimetric method for quantifying cell viability and proliferation by measuring mitochondrial metabolic activity. The method detects the conversion of the water-soluble tetrazolium salt MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) by active mitochondria, producing an insoluble purple formazan precipitate proportional to the number of viable cells. The related MTS assay, which does not require solubilization, offers improved kinetics and is now widely adopted in both academic research and pharmaceutical development.