The application of scanning force microscopy (SFM) in biology has increased during the last years because it allows measurements without pretreatment and under physiological conditions. In addition to pure imaging it is possible to use the SFM as a force sensor to detect forces as small as piconewtons. Such forces are relevant to interactions between bacterial cells and surfaces or biofilms on surfaces. Furthermore, the so-called mapping modes were recently developed as combinations of imaging and force spectroscopy modes. Especially in the field of biofilm formation the SFM allows to map biofilms, bacterial cells as well as cell properties by specifically applying functionalized or unfunctionalized tips. In this paper we provide a short survey of the opportunities of the SFM as a nano(mechanical) tool in the field of bacterial cell biology and want to provide practical advice for SFM on bacteria for beginners.
The application of the scanning force microscope on bacterial cells. Mapping is a combination of the imaging and force spectroscopy application and can be performed with a functionalized or unfunctionalized cantilever. The single cell force spectroscopy can be performed either on adsorbed cells or on a naked surface. The image is not to scale.