Atomic Force Microscopy: A Versatile Microscopy Resource on Campus

Authors

• EK Dimitriadis

Abstract

Atomic force microscopy (AFM) is a non-optical microscopy that employs a sharp (nm) probe to trace topographical features with sub-nm resolution. Moreover, the probe can be used to apply and/or measure forces with sensitivity of a few pN. A major advantage of AFM, compared to other high-resolution microscopies (e.g., EM), is that with minimal sample preparation and without the need for special staining, biological samples can be examined under ambient or physiological buffer conditions. Furthermore, force spectroscopy can be used to map material properties at the nanoscale. AFM is also combined with optical techniques, such as fluorescence, for co-localized observations. Here, we present a few examples of AFM applications including high resolution imaging and force spectroscopy. For example, we recently imaged and characterized fibers formed by several -Synuclein variants (a protein involved in Parkinson’s disease), to examine the role of charged residues in fiber formation. Another example concerns the mechanics of mucin granules. It was found that a newly discovered small protein affects the morphology of mucin granules. We measured membrane tension, hydrostatic pressure and elastic modulus of wildtype and knockout granules pointing to dramatic changes in mucin packaging and probably in the properties of the mucin layer over endothelial cells. Our facility operates several instruments each designed with certain applications in mind. Two are equipped with micro-incubators for live cell/tissue experiments and with fluorescence capabilities. One includes single-cell manipulation capabilities, including single-cell nano-injection. The facility is open to collaborations campus wide.

Scientific Focus Area: Biomedical Engineering and Biophysics

This page was last updated on Tuesday, August 6, 2024