Imaging with Photoelectrons

Extract

Most of us have used fluorescence microscopy and are all too familiar with the advantages and disadvantages of this tool: easy identification of one or more labels that fluoresce at different wavelengths (color) against the relatively dark background of the biologic substrate, but we can't always get the spatial resolution that is needed to answer our questions. Electron microscopy, both transmission and scanning modes, offer much better spatial resolution, but present problems in localizing a label, particularly on the surface of a cell. Wouldn't it be great if an imaging technique were available that gave us the possibility of localizing one or more labels on the surface of a cell with resolution approaching electron microscopy. Karen Hedberg, Bruce Birrel, Douglas Habliston, and Hayes Griffith at the University of Oregon describe photoelectron imaging as the electron optical analogue of fluorescence microscopy, offering some of the advantages of both methods.