Fluorescent real-time quantitative measurements of intracellular peroxynitrite generation and inhibition.

Peroxynitrite (ONOO), a strong oxidant species, is produced by the reaction of nitric oxide (NO) and superoxide (O) radicals. It plays an important role as a biological regulator in numbers of physiological and pathological processes. In this study, we developed fluorescence-based real-time quantitative measurements to detect intracellular ONOO. The probe DAX-J2 PON Green showed high selectivity toward ONOO over other competing species, and has been successfully applied in microplate reader and flow cytometer to quantitatively measure endogenous ONOO production. Moreover, the results demonstrated the inhibitory effects of curcumin on intracellular ONOO generation.