Reversible Reaction-Based Fluorescent Probe for Real-Time Imaging of Glutathione Dynamics in Mitochondria

We report a mitochondria-specific glutathione (GSH) probe—designated as Mito-RealThiol (MitoRT)—that can monitor in vivo real-time mitochondrial glutathione dynamics, and apply this probe to follow mitochondrial GSH dynamic changes in living cells for the first time. MitoRT can be utilized in confocal microscopy, super-resolution fluorescence imaging, and flow cytometry systems. Using MitoRT, we demonstrate that cells have a high priority to maintain the GSH level in mitochondria compared to the cytosol not only under normal growing conditions but also upon oxidative stress.