Superresolution Sharpens Images In Live Organisms

Nanoscale microscopy imaging techniques can now give researchers pictures from inside living multicellular organisms, expanding on previous work using superresolution methods to image cells in culture conditions. of the Max Planck Institute for Biophysical Chemistry, in Göttingen, Germany, and coworkers used stimulated emission depletion (STED) microscopy to image the distribution of proteins labeled with green fluorescent protein inside the roundworm Caenorhabditis elegans (Biophys. J.,10.1016/j.bpj.2011.05.020). In STED microscopy, one laser beam excites fluorescence from a label and another one turns fluorescence off everywhere except in a precisely defined nanometer-scale spot. With the technique, Hell and coworkers obtained 20- × 20-μm images of a pair of C. elegans serotonergic neurons. The axons of these neurons have clusters of tiny branches off the main axon branch called axon arbors. By taking stacks of images, the researchers reconstructed the 3-D morphology of the neurons. The STED images revealed a lack of connectivity between adjacent arbors and other morphological features that couldn’t be seen with conventional confocal microscopy.