Friday, February 17 at 2:00pm to 3:30pm
Andrus Gerontology Center (GER), 124
3715 McClintock Avenue, Los Angeles, CA 90089
Dr. William Moerner
2014 Nobel Prize in Chemistry
“The Story of Photonics and Single Molecules, from Early Spectroscopy in Solids, to Super-Resolution.
Nanoscopy in Cells and Beyond.”
Abstract: More than 25 years ago, low temperature experiments aimed at establishing the ultimate limits to optical storage in solids led to the first optical detection and spectroscopy of a single molecule in the condensed phase. At this unexplored ultimate limit, many surprises occurred where single molecules showed both spontaneous changes (blinking) and light-driven control of emission, properties that were also observed in 1997 at room temperature with single green fluorescent protein variants. In 2006, PALM and subsequent approaches showed that the optical diffraction limit of ~200 nm can be circumvented to achieve super-resolution fluorescence microscopy, or nanoscopy, with relatively nonperturbative visible light.
Essential to this is the combination of single-molecule fluorescence imaging with active control of the emitting concentration and sequential localization of single fluorophores decorating a structure. Super-resolution microscopy has opened up a new frontier in which biological structures and behavior can be observed in live cells with resolutions down to 20-40 nm and below. Examples range from protein superstructures in bacteria to bands in actin filaments to details of the shapes of amyloid fibrils and much more. Current methods development research addresses ways to extract more information from each single molecule such as 3D position and orientation, and to assure not only precision, but also accuracy. Still, it is worth noting that in spite of all the interest in superresolution, even in the “conventional” single-molecule tracking regime where the motions of individual biomolecules are recorded in solution or in cells rather than the shapes of extended structures, much can still be learned about biological processes when ensemble averaging is removed.
Biosketch: William Moerner is an American physical chemist and chemical physicist with current work in the biophysics and imaging of single molecules. He is credited with achieving the first optical detection and spectroscopy of a single molecule in condensed phases, along with his postdoc, Lothar Kador. Optical study of single molecules has subsequently become a widely used single-molecule experiment in chemistry, physics and biology. In 2014 he was awarded the Nobel Prize in Chemistry.
He attended Washington University in St. Louis for undergraduate studies as an Alexander S. Langsdorf Engineering Fellow, and obtained three degrees: a B.S. in physics with Final Honors, a B.S. in electrical engineering with Final Honors, and an A.B. in mathematics summa cum laude in 1975. This was followed by graduate study, partially supported by a National Science Foundation Graduate Fellowship, at Cornell University in the group of Albert J. Sievers III. Here he received an M.S. degree and a Ph.D. degree in physics in 1978 and 1982, respectively.