STED (IMAGE) Max-Planck-Gesellschaft Caption g-STED nanoscopy provides fundamentally improved spatial resolution over confocal microscopy in living cells. Here, the protein keratin is marked with the fluorescent protein Citrine in a living PtK2 cell. The insets show a magnified view of the marked areas, demonstrating the separation of features as small as 60 nm in the living cell. Fluorescence excitation at 485 nm, STED at 592 nm wavelength using a CW beam. Scale bars 1 μm Credit Max Planck Institute for Biophysical Chemistry Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.