In Germany, researchers at Philipps University in Marburg are testing a new generation of light microscopes made by Wetzlar-based Leica Microsystems GmbH, with a resolution well below the diffraction limit. With this new optical nanoscopy called GSDIM (ground state depletion microscopy followed by individual molecule return), scientists can achieve resolutions down to 25 nm. The technology makes it possible to image subcellular structures or protein complexes beyond the resolving powers of a light microscope. The new technology, for which Leica Microsystems has been granted an exclusive license, will be tested until September. It enables observation of molecular processes and true-to-detail imaging of the spatial arrangement of proteins and other biomolecules in cells.