Göttfert, F.; Pleiner, T.; Heine, J.; Westphal, V.; Görlich, D.; Sahl, S.; Hell, S. (2017) Strong signal increase in STED fluorescence microscopy by imaging regions of subdiffraction extent. PNAS. 114(9):2125-2130.
Great collaboration with the lab of Stefan Hell, using nanobodies as ultra-small immunolabels for stimulated emission depletion (STED) fluorescence microscopy. In STED the diffraction resolution barrier is overcome by applying a doughnut-shaped light beam that transiently switches fluorescence off, confining molecular emission to subdiffraction-sized regions around the doughnut center. Unfortunately, the doughnut intensities required for high resolution exacerbate photobleaching. Our remedy, called MINFIELD, exploits the fact that fluorescence off-switching by STED does not require the high intensities of the doughnut crest. By recording subdiffraction-sized areas or volumes in the sample, molecular exposure to high intensities is avoided and photobleaching is reduced by more than 100-fold.