Spatially resolved force spectroscopy of bacterial surfaces using force-volume imaging Export

@article{F.Gaboriaud.Rev.2007, abstract = {Force spectroscopy using the atomic force microscope (AFM) is a powerful technique for measuring physical properties and interaction forces at microbial cell surfaces. Typically for such a study, the point at which a force measurement will be made is located by first imaging the cell using AFM in contact mode. In this study, we image the bacterial cell Shewanella putrefaciens for subsequent force measurements using AFM in force-volume mode and compare this to contact-mode images. It is known that contact-mode imaging does not accurately locate the apical surface and periphery of the cell since, in contact mode, a component of the applied load laterally deforms the cell during the raster scan. Here, we illustrate that contact-mode imaging does not accurately locate the apical surface and periphery of the cell since, in contact mode, a component of the applied load laterally deforms the cell during the raster scan. This is an artifact due to the deformability and high degree of curvature of bacterial cells. We further show that force-volume mode imaging avoids the artifacts associated with contact-mode imaging due to surface deformation since it involves the measurement of a grid of individual force profiles. The topographic image is subsequently reconstructed from the zero-force height (the contact distance between the AFM tip and the surface) at each point on the cell surface. We also show how force-volume measurements yield applied load versus indentation data from which mechanical properties of the cell such as Young's modulus, cell turgor pressure and elastic and plastic energies can be extracted.}, author = {Gaboriaud, Fabien and Parcha, Bhargava S. and Gee, Michelle L. and Holden, James A. and Strugnell, Richard A.}, citeulike-article-id = {1769934}, citeulike-linkout-0 = {http://dx.doi.org/10.1016/j.colsurfb.2007.10.004}, citeulike-linkout-1 = {http://linkinghub.elsevier.com/retrieve/pii/S0927776507003967}, citeulike-linkout-2 = {http://www.sciencedirect.com/science/article/B6TFS-4PVPVMX-1/2/091b724247874cfb60b74a71f23489c0}, day = {01}, doi = {10.1016/j.colsurfb.2007.10.004}, issn = {09277765}, journal = {Colloids and Surfaces B: Biointerfaces}, keywords = {afm, atomic\_force\_microscopy, bacteria, cell, deformation, force\_measurements, force\_volume}, month = {April}, number = {2}, pages = {206--213}, posted-at = {2009-11-06 15:46:51}, priority = {2}, title = {Spatially resolved force spectroscopy of bacterial surfaces using force-volume imaging}, url = {http://dx.doi.org/10.1016/j.colsurfb.2007.10.004}, volume = {62}, year = {2008} }

TY - JOUR ID - F.Gaboriaud.Rev.2007 L3 - citeulike-article-id:1769934 N2 - Force spectroscopy using the atomic force microscope (AFM) is a powerful technique for measuring physical properties and interaction forces at microbial cell surfaces. Typically for such a study, the point at which a force measurement will be made is located by first imaging the cell using AFM in contact mode. In this study, we image the bacterial cell Shewanella putrefaciens for subsequent force measurements using AFM in force-volume mode and compare this to contact-mode images. It is known that contact-mode imaging does not accurately locate the apical surface and periphery of the cell since, in contact mode, a component of the applied load laterally deforms the cell during the raster scan. Here, we illustrate that contact-mode imaging does not accurately locate the apical surface and periphery of the cell since, in contact mode, a component of the applied load laterally deforms the cell during the raster scan. This is an artifact due to the deformability and high degree of curvature of bacterial cells. We further show that force-volume mode imaging avoids the artifacts associated with contact-mode imaging due to surface deformation since it involves the measurement of a grid of individual force profiles. The topographic image is subsequently reconstructed from the zero-force height (the contact distance between the AFM tip and the surface) at each point on the cell surface. We also show how force-volume measurements yield applied load versus indentation data from which mechanical properties of the cell such as Young's modulus, cell turgor pressure and elastic and plastic energies can be extracted. IS - 2 JF - Colloids and Surfaces B: Biointerfaces SN - 09277765 EP - 213 TI - Spatially resolved force spectroscopy of bacterial surfaces using force-volume imaging VL - 62 SP - 206 KW - afm KW - atomic_force_microscopy KW - bacteria KW - cell KW - deformation KW - force_measurements KW - force_volume AU - Gaboriaud, Fabien AU - Parcha, Bhargava AU - Gee, Michelle AU - Holden, James AU - Strugnell, Richard PY - 2008/04/01/ UR - http://dx.doi.org/10.1016/j.colsurfb.2007.10.004 ER -