MTT assay is a colorimetric reaction, generally used to examine cell viability. It involves the enzymatic reduction of a yellow-colored, water-soluble, 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) to purple-colored, water-insoluble, MTT-formazan. This reaction is catalyzed by mitochondrial dehydrogenase and only occurs in viable cells. Thus, the amount of blue formazan is proportional to the number of viable cells. The absorbance of the formazan solution is analyzed spectrophotometrically at 570 nm.
