A $1.1 million award from the National Science Foundation will enable the California NanoSystems Institute at UCLA to acquire the first commercially available superresolution stimulated emission depletion (STED) confocal laser scanning microscope for imaging biological samples at nanoscopic resolution. The STED concept relies on stimulated emission, coupled with smart optics, to sharpen the confocal excitation spot, resulting in more detailed, nanometer-resolved images. Bridging the gap between electron and diffraction-limited light microscopy, the STED microscope promises to be a powerful tool for unraveling the relationship between structure and function in cell biology.Superresolution STED microscopy holds great promise because it is expected to lead to significant new discoveries across the fields of biology, chemistry, materials sciences, engineering, medicine and physics. Researchers will use the microscope to investigate molecular assemblies at the nanoscale -- including deciphering the structure of chromatin and its packaging into chromosomes in the cell -- and to study cell signaling, viral and bacterial infection pathways, neural plasticity and many other important biological questions. They will also develop a new family of STED probes based on semiconductor nanocrystals. "Superresolution fluorescence microscopy will be decisive in solving long-lasting fundamental scientific questions which lie in this intermediate scale of tens of nanometers," said Laurent Bentolila, PhD, scientific director of the Advanced Light Microscopy/Spectroscopy lab. The device will be used at the Advanced Light Microscopy/Spectroscopy core laboratory of the California NanoSystems Institute (CNSI) by a multidisciplinary research team with expertise in physics, chemistry, imaging, genetics and molecular biology. The team will be led by principal investigator Shimon Weiss, UCLA professor of chemistry and biochemistry; and coprincipal investigators Michael Grunstein, UCLA professor of biological chemistry; and Bentolila, UCLA senior researcher in chemistry and biochemistry. The team will collaborate with Stefan W. Hell, director of the Max Planck Institute for Biophysical Chemistry in Germany. Developed by Leica Microsystems of Wetzlar, Germany, the microscope is designed for nanoscopic resolution of biological and artificial samples. Despite using regular lenses and visible light, the microscope is not limited by diffraction and diplays a 10X resolution improvement over conventional light microscopes. STED microscopy provides an alternative to electron microscopy because it capitalizes on the advantages of fluorescence microscopy -- including sensitivity, molecular specificity, genetically encoded probes, live cells and ease of operation. The CNSI Advanced Light Microscopy/Spectroscopy shared facility currently provides training to more than 250 undergraduate, graduate and postdoctoral research students. The STED microscope will be used to train and educate these students and researchers through a series of courses and will also be made available to a large network of researchers throughout Southern California and the US, the university said. For more information, visit: www.ucla.edu