FORLAB Cell Counting Kit-8 (CCK-8) Cell Proliferation Kit

Cell Counting Kit-8, abbreviated as CCK8 (or WST-8), is a rapid and sensitive assay for cell proliferation and cytotoxicity based on the colour reaction of WST-8 (2-(2-methoxy-4-nitrophenyl )-3-(4-nitrophenyl)-5-(2,4-disulfonatobenzene )-2H-tetrazole) monosodium salt). Rapid and highly sensitive assay for cell proliferation and cytotoxicity. 
WST-8 working principle: in the presence of electronically coupled reagents, it can be reduced by mitochondrial dehydrogenase to produce a highly water-soluble orange-yellow dirty product (formazan); the colour shade is directly proportional to the proliferation of the cell, and inversely proportional to the cytotoxicity; the OD value is measured using an enzyme marker at 450 nm, indirectly reflecting the number of viable cells. 
WST-8 is a kind of upgraded alternative product of MTT, which has obvious advantages compared with MTT or other MTT similar products, such as XTT, MTS, etc. First of all, MTT is reduced by some dehydrogenases in the mitochondrion to generate the dirty methanol which is not water-soluble, and needs a specific dissolution solution to be dissolved; and the dirty methanol generated by WST-8, XTT and MTS are all water-soluble, which can eliminate the need for subsequent dissolution of the dirty methanol. Secondly, the filth generated by WST-8 is easier to dissolve than that generated by XTT and MTS; again, WST-8 is more stable than XTT and MTS, which makes the experimental results more stable; in addition, the linear range of WST-8 is wider and the sensitivity is higher than that of MTT and XTT.
CCK method is widely used in drug screening, cell proliferation assay, cytotoxicity assay, tumour sensitivity assay and biofactor activity detection.