By Bjorn Carey
W.E. Moerner, the Harry S. Mosher Professor of Chemistry at Stanford, has been awarded the Nobel Prize in Chemistry "for having bypassed a presumed scientific limitation stipulating that an optical microscope can never yield a resolution better than 0.2 micrometers." Moerner shares the recognition with Eric Betzig, of Howard Hughes Medical Institute, and Stefan W. Hell, of the Max Planck Institute for Biophysical Chemistry, in Germany.
Optical microscopy was long limited by the presumption that it could never obtain a better resolution than half the wavelength of light. Moerner, Betzig and Hell circumvented this limitation through the clever implementation of fluorescent molecules, which made it possible for optical microscopes to operate at the nanoscale and visualize individual molecules moving within cells.
The Nobel Prize in Chemistry recognizes two separate techniques. One enables the method stimulated emission depletion (STED) microscopy, developed by Hell in 2000. Two laser beams are utilized; one stimulates fluorescent molecules to glow, another cancels out all fluorescence except for that in a nanometre-sized volume. Scanning over the sample, nanometer for nanometer, yields an image with a high resolution.
Betzig and Moerner, working separately, laid the foundation for the second method, single-molecule microscopy. The method turns the fluorescence of individual molecules on and off. Scientists image the same area multiple times, letting just a few interspersed molecules glow each time. Superimposing these images yields a dense super-image resolved at the nanolevel.
Together, these techniques have launched the field known as nanoscopy, allowing scientists to visualize the pathways of individual molecules inside living cells. They can see how molecules create synapses between nerve cells in the brain; they can track proteins involved in Parkinson’s, Alzheimer’s and Huntington’s diseases as they aggregate; they follow individual proteins in fertilized eggs as these divide into embryos.
Article posted from: http://news.stanford.edu/news/2014/october/moerner-nobel-prize-100814.html