WST1assays

WST1 assays are a type of colorimetric assay used to measure cell viability, proliferation, and cytotoxicity. The assay relies on the cleavage of the tetrazolium salt WST-1 (4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate) by mitochondrial dehydrogenases in viable cells. This cleavage results in the formation of a yellow-colored formazan dye, which is soluble in cell culture medium and can be quantified spectrophotometrically at a wavelength of approximately 450 nm.

WST1 assays are widely used in biomedical research due to their simplicity, sensitivity, and compatibility with various cell types. The assay is particularly useful for evaluating the effects of drugs, toxins, or other treatments on cell health. Unlike assays that rely on membrane integrity (such as MTT or LDH assays), WST1 specifically targets metabolically active cells, making it a more direct indicator of cell viability.

The procedure typically involves adding WST1 reagent to cell cultures, incubating for a defined period, and then measuring the absorbance of the supernatant. The intensity of the color is proportional to the number of viable cells, allowing for quantitative analysis. WST1 assays can be performed in microplates, making them suitable for high-throughput screening applications.

One advantage of WST1 assays is their non-destructive nature when used with short incubation times, enabling repeated measurements on the same cell population. However, prolonged incubation may lead to non-specific staining or interference from certain compounds. Proper controls, such as blank (medium-only) and positive (known viable cells) samples, are essential for accurate interpretation of results.

WST1 assays are commercially available as kits, often including optimized reagents and protocols, and are compatible with a range of cell culture formats, including adherent and suspension cells. They are frequently employed in drug discovery, toxicology studies, and basic cell biology research.