MTT assay

The MTT test is a test for determination of cell viability.

Principle

Cells in vitro, treated with the eponymous dye, a yellow tetrazolium salt to measure their viability or the percentage of living cells compared to a control sample of cells. This is necessary, for example, by testing a toxic substance.

The detection of cell viability by the MTT test is based on the reduction of yellow, water soluble dye 3 - (4,5- dimethylthiazol -2-yl ) -2,5- diphenyltetrazolium bromide (MTT ) to a blue-violet water-insoluble formazan. Previously, it was assumed that MTT is reduced by mitochondrial succinate dehydrogenase, investigations in the recent years, however, suggest that the reduction is mainly dependent on the pyridine- Reduktionsäquvivalenten NADH and NADPH, and only partially by succinate. The amount of the unreacted dye and ultimately measured corresponds to the glycolysis of the cells per se, and is thus less of a measure of cellular respiration ( as previously assumed ). The reduction of MTT by NADH and NADPH dependent enzymes of the endoplasmic reticulum. The partial reduction of MTT by succinate in the mitochondria is dependent on the other hand, the enzyme succinate dehydrogenase ( mitochondrial Complex II ).