Assay measures the increased activity of cellular mitochondrial dehydrogenases that can cleave the tetrazolium dye WST-1 to formazan. The formazan formation is then quantified by measuring the change in absorbance at 450 nm in a microplate reader. The activity of mitochondrial dehydrogenases is proportional to cell number. No washing, harvesting, or solubilization steps are required.

Sensitivity: 1000 cells (adherent); 2500 cells (nonadherent)

WST-1, 1-Methoxy PMS, and a user protocol.

Toxicity: Multiple Toxicity Values, refer to MSDS (O)

Assay Time: 0.5 - 4 h

The Calbiochem Rapid Cell Proliferation Kit is designed to determine the number of viable cells in proliferation, or cytotoxicity studies, based on the cleavage of the tetrazolium salt WST-1 by mitochondrial dehydrogenases in viable cells. The assay can be used to measure cell proliferation in response to growth factors or cytokines, or to assess cytotoxic compounds.

• WST-1 Labeling Mixture: Thaw the EMS solution at room temperature or in a 37°C water bath. Add the entire contents of this solution to the bottle containing the WST-1 reagent. The mixed solution can be stored at 4°C for several weeks. For long-term storage (several months) aliquot and store at -20°C. Protect from light.

Ishiyama, M., et al. 1995. In Vitro Toxicology8, 187.
Liu, S.O., et al 1995. Nat. Med.1, 267.
Ishiyama, M., et al. 1993. Chem. Pharm. Bull.41, 1118.

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