Whole-cell, 3D, and multicolor STED imaging with exchangeable fluorophores
Spahn, C., Grimm, J. B., Lavis, L. D., Lampe, M., & Heilemann, M.
Exchange-based STED microscopy, PAINT, fluorogenic labels, multicolor imaging, volumetric imaging, live-cell STED microscopy
We demonstrate stimulated emission depletion (STED) microscopy of whole bacterial and eukaryotic cells using fluorogenic labels that reversibly bind to their target structure. A constant exchange of labels guarantees the removal of photobleached fluorophores and their replacement by intact fluorophores, thereby circumventing bleaching-related limitations of STED super-resolution imaging. We achieve a constant labeling density and demonstrate a fluorescence signal for long and theoretically unlimited acquisition times. Using this concept, we demonstrate whole-cell, 3D, multicolor, and live-cell STED microscopy.