| Autor: |
Hafi N; 1] Department of Biophysical Chemistry, Institute for Physical and Theoretical Chemistry, University of Braunschweig, Braunschweig, Germany. [2]., Grunwald M; 1] Biomolecular Spectroscopy and Single-Molecule Detection Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany. [2]., van den Heuvel LS; 1] Department of Biophysical Chemistry, Institute for Physical and Theoretical Chemistry, University of Braunschweig, Braunschweig, Germany. [2]., Aspelmeier T; 1] Felix Bernstein Institute for Mathematical Statistics in Bioscience, Göttingen, Germany. [2] Institute for Mathematical Stochastics, University of Göttingen, Göttingen, Germany. [3] Statistical Inverse Problems in Biophysics Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany. [4]., Chen JH; Biomolecular Spectroscopy and Single-Molecule Detection Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany., Zagrebelsky M; Division of Cellular Neurobiology, Zoological Institute, University of Braunschweig, Braunschweig, Germany., Schütte OM; Institute of Organic and Biomolecular Chemistry, University of Göttingen, Göttingen, Germany., Steinem C; Institute of Organic and Biomolecular Chemistry, University of Göttingen, Göttingen, Germany., Korte M; Division of Cellular Neurobiology, Zoological Institute, University of Braunschweig, Braunschweig, Germany., Munk A; 1] Felix Bernstein Institute for Mathematical Statistics in Bioscience, Göttingen, Germany. [2] Institute for Mathematical Stochastics, University of Göttingen, Göttingen, Germany. [3] Statistical Inverse Problems in Biophysics Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany., Walla PJ; 1] Department of Biophysical Chemistry, Institute for Physical and Theoretical Chemistry, University of Braunschweig, Braunschweig, Germany. [2] Biomolecular Spectroscopy and Single-Molecule Detection Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany. |
| Abstrakt: |
When excited with rotating linear polarized light, differently oriented fluorescent dyes emit periodic signals peaking at different times. We show that measurement of the average orientation of fluorescent dyes attached to rigid sample structures mapped to regularly defined (50 nm)(2) image nanoareas can provide subdiffraction resolution (super resolution by polarization demodulation, SPoD). Because the polarization angle range for effective excitation of an oriented molecule is rather broad and unspecific, we narrowed this range by simultaneous irradiation with a second, de-excitation, beam possessing a polarization perpendicular to the excitation beam (excitation polarization angle narrowing, ExPAN). This shortened the periodic emission flashes, allowing better discrimination between molecules or nanoareas. Our method requires neither the generation of nanometric interference structures nor the use of switchable or blinking fluorescent probes. We applied the method to standard wide-field microscopy with camera detection and to two-photon scanning microscopy, imaging the fine structural details of neuronal spines. |
