Purity >95%. Lucigenin is a dual purpose probe. It can be used as a chemiluminescent probe to detect superoxide production by enzymatic and cellular sources. It is a very sensitive method that has been applied to the monitoring of superoxide production from xanthine oxidase, microsomal NADPH cytochrome reductase, and NADPH oxidases of phagocytes, endothelial cells, fibroblasts, and smooth muscle cells of blood vessel walls. Lucigenin is also used as a fluorescent chloride-sensitive indicator, with fluorescence being quenched by chloride (excitation: 455 nm; emission: 505 nm). Lucigenin fluorescence is insensitive to phosphate, sulfate, and nitrate.