Principle
The stable tetrazolium salt WST-1 is cleaved to a soluble formazan by a complex cellular mechanism that occurs primarily at the cell surface. This bioreduction is largely dependent on the glycolytic production of NAD(P)H in viable cells. Therefore, the amount of formazan dye formed directly correlates to the number of metabolically active cells in the culture.
Cells, grown in a 96-well tissue culture plate, are incubated with the ready-to-use WST-1 reagent for approximately 0.5 - 4 hours. After this incubation period, the formazan dye formed is quantitated with a scanning multi-well spectrophotometer (ELISA reader). The measured absorbance directly correlates to the number of viable cells.
Contents
Ready-to-use solution, containing WST-1 and an electron coupling reagent
Product Description
Sample material: Adherent or suspension cells cultured in 96-well microplates.
Benefits
Safe, since the assay does not use radioactive isotopes.
Accurate, since assay absorbance strongly correlates to the cell number.
Sensitive, since the assay can detect even low cell numbers.
Fast, since the assay can be read in a multi-well ELISA reader, which allows simultaneous processing of many samples.
Easy, since the assay does not require any washing steps or additional reagents.
Convenient, since the assay reagent is ready to use.
Background Information
There are several colorimetric assays that can analyze the number of viable cells; each is based on the cleavage of tetrazolium salts that are added to the culture medium. These assays do not require either washing or harvesting of cells. The complete assay, from microculture to data analysis, can be performed in the same microplate.
Application
Use Cell Proliferation Reagent WST-1 to assay cell proliferation and viability of cell populations.  Possible applications include:
Measurement of cell proliferation in response to growth factors, cytokines, mitogens, and nutrients.
Analysis of cytotoxic and cytostatic compounds, such as anti-cancer drugs and other pharmaceutical compounds.
Assessment of antibodies and physiological mediators that inhibit cell growth.