The DCFDA ROS Assay kit utilizes 2’,7’ –dichlorofluorescin diacetate (DCFDA), a cell permeable reagent, to detect reactive oxygen species in live cells. DCFDA is capable of measuring hydroxyl, peroxyl, and other reactive oxygen species activity within the cell. When DCFDA enters the cell, it is deacetylated by cellular esterases into a non-fluorescent compound. Then, it is oxidized by reactive oxygen species into 2’, 7’ –dichlorofluorescein (DCF), which is highly fluorescent and can be detected by fluorescence spectroscopy at excitation and emission wavelengths of 485 nM and 535 nM, respectively.
 
For this assay, the cells are first stained with DCFDA. Then, the cells can be treated with compound(s) of interest and measured using a fluorescent plate reader.