AFM imaging of TMV

Can we estimate the impact of AFM perturbation to an imaged single molecule?

Schematic cross-section of a single TMV particle. X-ray diffraction shows that TMV has a diameter of 19 nm. By changing the sample substrate (mica on the left and self-assembled monolayers, SAM, on the right) and by changing imaging parameters (Liq for liquid, PFT for PeakForce Tapping, TAP for Tapping), we can clearly note changes in the TMV height (diameter). It is shown that the choice of the substrate brings the largest changes in TMV height. This study also shown that TMV imaging in air is perfectly possible at the condition of using a "soft" substrate and a soft imaging mode. AFM measurements were made over several years with Christian Godon, Jean-Marie Teulon, and Michael Odorico. TMV purification was performed by Christian Basset. SAM surfaces were produced by Matthieu Meillan under the supervision of Luc Vellutini. The analytical image processing and height computation was developped by Wendy Chen.

Godon C, Teulon J-M, Odorico M, Basset C, Meillan M, Vellutini L, Chen S-wW and Pellequer J-L (2017) Conditions to minimize soft single biomolecule deformation when imaging with atomic force microscopy. J. Struct. Biol. 197: 322-329.