WST-1 assay is a popular colorimetric assay determining the
number of living cells. Membrane impermeable tetrazolium
WST-1 is reduced by intracellular NAD(P)H through membrane
permeable redox mediator 1-methoxyPMS, and the absorbance of
the resulting coloured formazan is proportional to the cell viability
depending on the productivity of NAD(P)H in cells (Ishiyama et al.,