Irradiance dependence of photobleaching of resorufin

Resorufin is a fluorescent reporter molecule, the end product in a variety of biochemical analyses. In such assays, excitation sources with high intensity are desirable for fast and precise results. However, high intensity sources bleach resorufin. We report quantitative bleaching rates for resorufin subjected to green excitation over an irradiance range of 5 to about 600 mW/cm2.