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Departmental Colloquium

Breaking Speed and Resolution Limitations of AFM  
Guest Speaker
Prof. Simon Scheuring  
Guest Affiliation
Weill Cornell Medicine, Department of Anesthesiology, Department of Physiology and Biophysics, New York  
Thursday, October 14, 2021 3:55 pm - 4:55 pm  
Zoom Meeting  

High-speed atomic force microscopy (HS-AFM) is a powerful technique that provides dynamic movies of biomolecules at work. We successfully used HS-AFM to take movies – and determine dynamic parameters – of membrane trafficking systems such as ESCRT-III and clathrin, transporters and channels.

To break current temporal limitations to characterize molecular dynamics using HS-AFM, we developed HS-AFM height spectroscopy (HS-AFM-HS), a technique whereby we oscillate the HS-AFM tip at a fixed position and detect the motions of the molecules under the tip. This gives sub- nanometer spatial resolution combined with microseconds temporal resolution of molecular fluctuations. HS-AFM-HS can be used in conjunction with HS-AFM imaging modes, thus giving access to a wide dynamic range.

To break current resolution limitations, we developed Localization AFM (LAFM). By applying localization image reconstruction algorithms to peak positions in high-speed AFM and conventional AFM data, we increase the resolution beyond the limits set by the tip radius and reach quasi-atomic resolution on soft protein surfaces in native and dynamic conditions. The LAFM method allows the calculation of high-resolution maps from either images of many molecules or many images of a single molecule acquired over time, opening new avenues for single molecule structural analysis.