Quantitative Real-Time Imaging of Glutathione with Sub-Cellular Resolution

Quantitative imaging of glutathione with high spatial and temporal resolution is essential for studying the roles of glutathione in redox biology. We developed a fluorescent glutathione probe--HaloRT--that targets organelles of interest through expressing organelle-specific HaloTag proteins. Using HaloRT, we quantitatively measure the glutathione concentrations in the nucleus and the cytosol and find no appreciable concentration gradient between these two organelles, challenging the view of nuclear compartmentalization of glutathione.