High-Speed AFM Studies of Cell Membrane Dynamics

A. Slade, J. Kindt, S. Minne
Bruker, US

Keywords: high speed AFM, SPM, atomic force microscopy, cell membrane dynamics

Summary:

The ability of atomic force microscopy (AFM) to obtain three-dimensional topography images of biological molecules and complexes with nanometer resolution and under near-physiological conditions remains unmatched by other imaging techniques. Live cell imaging is one of the most challenging applications for AFM. The large topography and extremely soft nature of cells requires large AFM scanner ranges, very flexible cantilevers, and highly sensitive force control between the AFM probe and the cell surface. In this presentation we will show the first high-resolution, HS-AFM images of the supramolecular structure of the bacterial outer membrane (OM) obtained directly on the surface of live cells. In addition to resolving nanoscale features on the outer membrane surface of Escherichia coli, the increased time resolution of HS-AFM allowed us to observe dynamic changes in the membrane structure of individual E .coli cells in direct response to the antimicrobial peptide (AmP) CM15 with nanometer spatial resolution and at timescales relevant to the biological mechanism of AmP-induced cell death. Correlating HS-AFM studies were also conducted on supported lipid bilayers used as model cell membrane systems