Single-molecule fluorescence imaging enables biophysical measurements in cells without ensemble averaging, but also yields enhanced spatial resolution surpassing the diffraction limit (super-resolution) when combined with active control of the single emitters to maintain sparse concentrations. Using photoinduced blinking and/or photoswitching/photoactivation of fluorescent proteins, a variety of cellular superstructures have been imaged with sub-40 nm resolution. Several approaches lead to 3D imaging; the double-helix point spread function enables quantitative tracking of single mRNA particles in living yeast cells as well as 3D images in bacterial and eukaryotic cells with relatively uniform localization precision over a large depth of field (microns).
W. E. Moerner, the Harry S. Mosher Professor of Chemistry and professor, by courtesy, of Applied Physics at Stanford University, conducts research in physical chemistry of single molecules, biophysics, nanoparticle trapping, and nanophotonics. He earned three bachelor's degrees from Washington University in 1975 and master's and doctoral degrees from Cornell University in 1978 and 1982. From 1981 to 1995, he was a research staff member at IBM, receiving two IBM Outstanding Technical Achievement Awards. He was Professor and Distinguished Chair in Physical Chemistry at the University of California, San Diego, from 1995 to 1998, the year he joined the Stanford faculty.
Moerner is a member of the National Academy of Sciences, and co-recipient of the Wolf Prize in Chemistry (with Allen Bard) in 2008. He and Bard were cited for "the ingenious creation of a new field of science, single molecule spectroscopy and electrochemistry, with impact at the nanoscopic regime, from the molecular and cellular domain to complex material systems."