A method to detect several forms of reactive oxygen species (ROS). Superoxide is detected with OxyBURST Green H2DCFDA or OxyBURST Green H2HFF BSA, and hydrogen peroxide using Carboxy-H2DCFDA and CMH2DCFDA. Detection is possible as a result of the increasing fluorescence of the dye when one of ROS listed above is present in the analysed sample.