Cell proliferation can be detected by a variety of methods. Cell proliferation induces an increase in the activity of the mitochondrial dehydrogenases, which cleaves the tetrazolium salt WST-1 to formazan.

 The ready-to-use cell proliferation reagent, WST-1 provides an accurate and simple way for quantification of cell proliferation. Cell proliferation causes the increase in the amount of formazan dye formed that can be quantified by measuring the absorbance of the dye solution at 440 nm using microtiter plate reader. WST-1 can be used for the analysis of cell proliferation in response to pharmaceutical compounds, cytotoxic compounds like anticancer drugs and many other toxic agents. The assay can also be used for the detection of cell proliferation in response to cytokines, mitogens, growth factors and nutrients, etc and be used for the assessment of antibodies and physiological mediators that inhibit cell growth. The assay is rapid, non-radioactive and more sensitive than MTS, MTT or XTT-based assays. The entire assay can be performed in the same microtiter plate requiring no solubilization, no washing and no harvesting steps.