This kit is a convenient tool for the detection of Hydroxyl Radical Antioxidant Capacity. The principle is based ona fluorescein sodium fluorescent probe. Fenton reaction produces hydroxyl radicals. According to the damage caused to the fluorescent probe by the hydroxyl radicals, the fluorescence intensity changes; the change of fluorescence intensity reflects the degree of free radical damage. In the presence of antioxidants, hydroxyl free radical damage is inhibited.