CCK-8 reagent kit is a fast and highly sensitive detection kit widely used for cell proliferation and cytotoxicity based on WST-8. WST-8 is a compound similar to MTT that can be reduced to form orange yellow water-soluble formazan in the presence of electron coupling reagent 1-MethodyPMS. The more cells proliferate, the faster the color becomes; The greater the cytotoxicity, the lighter the color. For the same cells, there is a linear relationship between the depth of color and the number of cells.