I want to determine whether elevated amount of OH., super-oxide radical and hydrogen peroxide were produced and create oxidative stress during cancer treatment or not by molecular imaging technique.
The CM-H2DCFDA assay is indeed a very practical experiment to evaluate peroxide activity. You can perform a standard curve with increasing H2O2 concentrations using a plate reader at fluorescein wavelength excitation/emission.
Practically, to assay the superoxide radicals generated in cells is a difficult task because of its short half-life. H2O2 levels is a standard measurement of oxidative stress. Definitely you can go for CM-H2DCFDA as a broad range oxidative stress marker. Particularly for H2O2 measurement you can use Amplex® Red.