Resazurin sodium salt

Resazurin (also known as Alamar Blue), is the N-oxide of the fluorescent dye resorufin. It is useful for detecting reductive activities in cells and has been widely used for measuring cell proliferation and mitochondrial metabolic activity. It is used as a quantifiable detection agent for enzyme activity assays and as an oxidation-reduction indicator in cell proliferation, cell viability and cytotoxicity assays.

Resazurin is a non-toxic, water-soluble and redox-sensitive dye that is non-fluorescent until it is reduced to the highly red fluorescent resorufin (λEx/λEm: 563/587 nm). Usually, NADPH or NADH is the reductant that converts resazurin to resorufin in the presence of diaphorase as the enzyme. Thus, resazurin can be used to detect NADH, NADPH, or diaphorase levels. Furthermore, the resazurin/diaphorase/NADPH system can be used to detect any biochemical or enzyme activity that is involved in a biochemical reaction generating NADH or NADPH.