Our Cell Counting Kit-8 (A014-1, A014-2), Cell-Quant™ MTT Cell Proliferation Assay Kit (A015) and Cell-Quant™ AlamarBlue Cell Viability Reagent (A016-1, A016-2) utilize metabolic indicators to measure cellular reduction potential. In the CCK-8 assay, the WST-8 reagent is reduced by dehydrogenase activities in cells to give a yellow-color formazan dye, which is soluble in the tissue culture media. The amount of the formazan dye, generated by the activities of dehydrogenases in cells, is directly proportional to the number of living cells. In the MTT assay, the MTT reagent is reduced by metabolically active cells to a strongly colored reporter, formazan. The signal is proportional to the number of live cells, thus allowing an accurate quantification of changes in the rate of cell proliferation. Similarly, our AlamarBlue reagent (resazurin) is converted to the fluorescent and colorimetric reporter molecule resorufin in metabolically active cells (Figure 1).
Figure 1. The assay principle of CCK-8 and AlarmarBlue.
Figure 2. Dose response curve of ellipticine in HepG2 cell line using the AlamarBlue and MTT assays.