Nov 5 2007
The National Science Foundation has awarded a $1.1 million Major Research Instrumentation grant for the Advanced Light Microscopy core laboratory at the California NanoSystems Institute at UCLA. The award will facilitate the acquisition of the first commercially available super-resolution stimulated emission depletion (STED) confocal laser scanning microscope for nanoscopic resolution of biological samples.
The device will be used by a multidisciplinary research team with expertise in physics, chemistry, imaging, genetics and molecular biology led by principal investigator Shimon Weiss, UCLA professor of chemistry and biochemistry, and co-principal investigators Michael Grunstein, UCLA professor of biological chemistry, and Dr. Laurent 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.
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.
"We have assembled a group of multidisciplinary UCLA users who will significantly advance their research by making use of this instrument," said Weiss, who is also a member of the California NanoSystems Institute (CNSI) at UCLA.
Developed by Leica Microsystems, the microscope is uniquely 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 x10 resolution improvement over conventional light microscopes.
STED microscopy provides an alternative to electron microscopy because it capitalizes on the well-established advantages of fluorescence microscopy - including sensitivity, molecular specificity, genetically encoded probes, live cells and ease of operation.
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.
The CNSI Advanced Light Microscopy/Spectroscopy shared facility currently provides training to more than 250 research students at the undergraduate, graduate and postdoctoral levels. The new microscope will be used in the education and training of students and researchers through a series of courses offered by the facility. The instrument will also be made available to a large network of researchers throughout Southern California and the United States.
Super-resolution 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.
"Super-resolution fluorescence microscopy will be decisive in solving long-lasting fundamental scientific questions which lie in this intermediate scale of tens of nanometers," said Bentolila, director of the Advanced Light Microscopy core lab at the CNSI.