Lecture: Cryogenic Super-Resolved Fluorescence Microscopy

04.10.2016, 10:00

Siegfried Weisenburger, Laboratory of Neurotechnology and Biophysics, The Rockefeller University, New York

Place:

Large Seminar Room (435), MPL, Günther-Scharowsky-Str. 1, Building 24, Erlangen

 

Abstract:

Super-resolved fluorescence microscopy, which was awarded the Nobel Prize in Chemistry last year, allows us to resolve sub-cellular structures at an optical resolution beyond the diffraction limit. Imagine we could increase the resolution by another two orders of magnitude to directly resolve sub-molecular structures such as constituents of biomolecule complexes or even protein structure itself.

 

In this talk, I will introduce our cryogenic localization microscopy method that, due to the substantial improvement of the molecular photostability at liquid helium temperature, allows for single-molecule localization at the Angstrom level. I will also present the first adaptation of this technique to super-resolution imaging of whole cells. Measurements on frozen CHO cells stably expressing dopamine D2 receptors allowed us to determine the distance between the protomers of receptor homodimers. Finally, I will present our results on resolving the positions of multiple fluorophores attached to proteins. By applying algorithms borrowed from cryogenic electron microscopy, we can reconstruct a three-dimensional density map for the positions of the fluorescent labels with a resolution of a few Angstroms, yielding excellent agreement with a homology model. Our technique allows us to gain structural information that might not be accessible via existing analytical methods such as x-ray crystallography or magnetic resonance spectroscopy. These results show that optical resolution can be pushed beyond conventional super-resolution microscopy by nearly one hundred times.