Atomic Force Microscopy

Atomic force microscopy is an emerging tool to study biological macromolecules and dynamic biological processes in a native environment. We start this chapter with a description of contrast generation in the Atomic Force Microscope (AFM) and the different imaging modes. In the next section, sample preparation strategies are presented and explained. After summarising the fundamentals of image analysis, we outline how resolution depends on the imaging environment and how images of unperturbed biological systems can be obtained. Finally, examples highlight the capabilities of the AFM to observe sub-structures and the assembly of single proteins at sub-nanometer resolution, as well as dynamic bio-molecular systems and cells. In the last section, we discuss applications of the technique for purposes other than imaging. Examples from such experiments demonstrate that AFM allows measuring interaction forces, ranging from the adhesion between cells down to the interactions that stabilise single proteins.