Cell Counting Kit-8 (CCK-8) allows sensitive colorimetric assays for the determination of cell viability in cell proliferation and cytotoxicity assays. Dojindo’s highly water-soluble tetrazolium salt, WST-8, 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. The detection sensitivity of CCK-8 is higher than the other tetrazolium salts such as MTT, XTT, MTS or WST-1.
Features
1) No radioisotope is required as in the [3H]-thymidine incorporation assay.
2) Both tetrazolium salts and formazan are highly water-soluble, eliminating the need to dissolve formazan as in the MTT assay.
3) Higher sensitivity and lower toxicity than other water-soluble tetrazolium salts (XTT, MTS).
4) No reagent preparation is required because it is a single-bottle solution type.
5) Reagent is more stable than other assay kits.
6) Can be used with media containing phenol red.
The “Chromogenic Substrate WST Series” and “Cell Counting Kit-8” were originally developed by Dojindo and are used worldwide for cell proliferation and cytotoxicity tests.
Cell Proliferation / Cytotoxicity Assay_CCK-8
Cell Counting Kit-8 vs MTT
Technical info
Cell Counting Kit-8 requires 3 simple steps:
The handling time of Cell Counting Kit-8 is the shortest among its competitors. Only 15 minutes of handling time is needed for Cell Counting Kit-8, whereas longer handling time is required for both MTS and MTT assay.
Unlike MTT assay, there is no need to lyse cells, so you don’t have to worry about the data variation.
Sensitivity
CCK-8 (WST-8) is the highest sensitive dye for the cell based assay.
Sensitivity Comparison using Tetrazolium Dye
Cytotoxicity of Reagents
Only in CCK-8, continious culture is possible without killing cells.
Observation of Cytotoxicity after incubation with each reagent.
HeLa cells were incubated with WST-8 (CCK-8), WST-1, or MTS at 24 hours from addition of those reagents.
Stability
Cell Counting Kit-8 is a ready-to-use solution stable at 4ºC for 1 year. Assays can be completed anytime without thawing and freezing.
Simultaneous usage of CCK-8 and Cytotoxicity LDH Assay Kit-WST
Since Cell Counting Kit-8 measures the metabolic activity of living cells, the data does not specifically verify cell death. To ensure the data is reflecting the cell death instead of decreased metabolic activity, Cytotoxicity LDH Assay Kit-WST (CK12) is used to increase the data reliability by measuring LDH released from dead cells.
Example Data using Cell Counting Kit-8
Data for Cell Proliferation and Cytotoxicity Assay
Cell Viability Determination
Data was kindly provided by Reaction Biology Corporation.
Absorption property of WST-8
The microplate reader with a 450-490 nm filter is applicable for the measurement.
Absorption spectrum of WST-8 formazan dye
Application Data: Alteration of intracellular metabolism of HeLa cells by treatment with fatty acid transporter inhibitors
Fatty acids are important for membrane synthesis and are essential for cell proliferation. HeLa cells were treated with a fatty acid transporter inhibitor, and then the cell proliferation and intracellular metabolism (glucose consumption, Lactate release, and NAD/NADH ratio) were tested.
The results showed a decrease in cell proliferation, an increase in glucose consumption and Lactate release, and a decrease in the intracellular NAD+/NADH ratio, indicating a shift in the metabolic pathway to glycolysis.
＜Related Products＞
Cell Proliferation: Cell Counting Kit-8 (Code: CK04)
Glucose: Glucose Assay Kit-WST (Code: G264)
Lactate: Lactate Assay Kit-WST (Code: L256)
NAD/NADH Ratio: NAD/NADH Assay Kit-WST (Code: N509)
