The Premix WST-1 Cell Proliferation Assay System allows fast and easy colorimetric measurement of cell proliferation and viability in a 96-well format, without radioactive isotopes or organic solvents. The Premix WST-1 Cell Proliferation Assay System is also applicable to cytotoxicity and inhibitory assays, where dye production decreases rather than increases.

The colorimetric assay is based on the cleavage of the tetrazolium salt WST-1 to a formazan-class dye by mitochondrial succinate-tetrazolium reductase in viable cells. As the cells proliferate, more WST-1 is converted to the formazan product. The quantity of formazan dye is directly related to the number of metabolically active cells, and can be quantified by measuring absorbance at 420–480 nm (A_max 450 nm) in a multiwell plate reader.

An effortless protocol

No washing, harvesting, or solubilization steps are required with the Premix WST-1 Cell Proliferation Assay System. The entire procedure, from cell culture to data analysis, can be carried out with a multiwell plate reader in the same 96-well plate.

Once your cells are cultured, the assay can be completed in approximately 1 hour. Simply add the Premixed WST-1 Cell Proliferation Reagent to the plate, culture your cells for at least 30 min in a humidified atmosphere (up to 4 hr, depending on cell type and density) and measure the absorbance. The colored product is generated continuously, so you can monitor the progress of your experiment over time by repeatedly reading the plate and returning it to the incubator for further development. This eliminates guesswork and ensures that the optimal assay endpoint is not overlooked.

Stable reagents

Unlike traditional WST-1 assay reagents, which can only be stored for three days at 4°C or one month at –20°C, the Premixed WST-1 Cell Proliferation Reagent has been formulated for increased stability: it can be stored for two weeks at 4°C or one year at –20°C. It is supplied as a ready-to-use solution containing WST-1 and an electron-coupling reagent, diluted in sterile phosphate-buffered saline.

Non-radioactive, colorimetric assay

Many cell proliferation assays are based on measurements of radioactively labeled nucleoside uptake during DNA synthesis. The Premixed WST-1 Cell Proliferation Reagent assay is nonradioactive, which enhances convenience and laboratory safety. Furthermore, the Premixed WST-1 Cell Proliferation Reagent is highly water-soluble compared to other tetrazolium salts used in similar assays, which may require surfactants or organic solvents for dissolution.

The Premixed WST-1 Cell Proliferation Reagent will simplify and streamline your cell proliferation assays. The simple, one-solution protocol saves time and is easy to use in a 96-well plate format. Plates can be read and returned to the incubator for further development to simplify time-course experiments.