What is a WST 1 assay?

WST-1 Assay Reagent ab155902 provides a simple, accurate and ready-to-use assay to measure cell proliferation, cell viability and cytotoxicity in mammalian cells. The WST-1 assay protocol is based on the cleavage of the tetrazolium salt WST-1 to formazan by cellular mitochondrial dehydrogenases.

What is formazan Crystal?

Formazan dyes are artificial chromogenic products obtained by reduction of tetrazolium salts by dehydrogenases and reductases. They have a variety of colors from dark blue to deep red to orange, depending on the original tetrazolium salt used as the substrate for the reaction.

What is an XTT assay?

The XTT assay is used to measure cellular metabolic activity as an indicator of cell viability, proliferation and cytotoxicity.

What is a cell proliferation assay?

Cell proliferation assays are designed to quantify the relative rates of cell division within such target tissues using specialized immunohistochemical staining techniques to detect proliferating cells.

How do you increase cell viability?

Cell viability can be improved with gentle handling and the correct tools. It is always wise to opt for wide bore tips when pipetting fragile cell samples, as they have a larger orifice for cells to flow through.

Why DMSO is added in MTT assay?

DMSO is added at the end of the reaction to dissolve the formazan crystals formed from the reaction. Otherwise, you can not properly measure the color density of the reaction. DMSO is added only after incubation with MTT dye, after you remove the medium from cells, in order to dissolve formazan crystals.

What is formazan used for?

IMPORTANCE Reduction of the water-soluble tetrazolium salt 3-(4,5-dimethylthiazol)-2,5 diphenyl-tetrazolium bromide (MTT) to purple, water-insoluble formazan is commonly used for assessment of cell viability and proliferation.

How do you dissolve formazan crystals?

If you want to dissolve formazan crystals, you just have to remove the cell culture medium and add 100% DMSO into wells. We usually add 100 ul DMSO into each well of 96-well plate. Formazan is not very well soluble in DMSO, thus you may need to leave a plate on a shaker (very low speed) for 15-20 min.

Why should I use XTT instead of MTT?

MTT is not a soluble product, so the cells must be lysed to solubilize the formazan salt before absorbance can be measured. XTT and resazurin do not require cell lysis, allowing kinetic monitoring of the same samples at different timepoints.

What does MTT stand for in MTT assay?

This colorimetric assay is based on the reduction of a yellow tetrazolium salt (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide or MTT) to purple formazan crystals by metabolically active cells (Figure 1).