Single fluorescent probe distinguishes hydrogen peroxide and nitric oxide in cell imaging.

In combination with synthetic fluorescent probes, fluorescence microscopy has emerged as a powerful technique to investigate the production, localization, trafficking, and function of biomolecules in living systems in a noninvasive manner. Prompted by our interest in providing a molecular tool to disentangle the complicated interrelationship between H2O2 and NO in the signal transduction and oxidative pathways, our laboratory has developed a single fluorescent probe, FP-H2O2-NO, that can report H2O2, NO, and H2O2/NO with three different sets of fluorescence signal patterns. In this chapter, we provide essential information about the probe FP-H2O2-NO in order to assist researchers interested to apply our probe to investigate H2O2 and NO biology. We describe the use of FP-H2O2-NO with the representative examples of imaging both exogenous and endogenous H2O2 and NO in live Hela and RAW 264.7 macrophage cells by fluorescence microscopy.