Cellular Reactive Oxygen Species (ROS) Detection Assay Kit #13323

Reactive oxygen species (ROS) include a variety of highly reactive oxidant molecules and free radicals that are derived from molecular oxygen. ROS are generated as a result of both normal cellular metabolism and environmental factors including air pollutants or cigarette smoking. The major ROS of physiological significance are superoxide anions (O₂^-.), hydroxyl radicals (^.OH), and hydrogen peroxide (H₂O₂) (1-3). Low to moderate ROS levels play important roles in normal physiological processes including vascular tone regulation, oxygen sensing, immunological reaction, regulation of translation, and signal transduction. High ROS concentrations can lead to adverse modifications of cellular components, such as carbohydrates, lipids, proteins, and DNA. Many of these modifications have been linked to diseases including atherosclerosis, diabetes, cancer, and neurological disorders. As a result, regulation of reducing and oxidizing (redox) state is not only critical for cell health, but is also an attractive therapeutic target for many diseases (1-3).

2′,7′-Dichlorodihydrofluorescein diacetate (DCFH-DA) is a non-fluorescent fluorescein derivative used as a non-ionic, non-polar, cell membrane permeable dye. After crossing the cell membrane, DCFH-DA is hydrolyzed by intracellular esterases to a non-fluorescent dichlorodihydrofluorescein (DCFH). DCFH is relatively more polar and cell membrane-impermeable and thus accumulates in cells. In the presence of cellular ROS, DCFH is oxidized to the highly fluorescent dichlorofluorescein (DCF). The fluorescent intensity of DCF is proportional to the overall cellular ROS level (4,5).