CCK-8 Cell Counting Kit is based on WST-8 [2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt] that is rapidly absorbing, highly sensitive and widely used in detection of cellproliferation and cytotoxicity. The amount of formazan dye generated by dehydrogenases in living cells is directly proportional to the number of living cells. Measure the Optical Density at 450 nm, using a microplate reader. The measurements can be indirectly shows the number of living cells. CCK-8 Cell Counting Kit contains CCK-8 Solution, which is a ready-to-use reagent. CCK-8 Solution can be directly added to cell samples. After Incubating the mixed solution for a certain period of time, the assay can be performed without preparing various components in advance.