The atomic force microscope (AFM) is an important tool for studying biological samples due to its ability to image surfaces under liquids. The AFM operates by physical interaction of a cantilever tip with the molecules on the cell surface. Adhesion forces between the tip and cell surface molecules are detected as cantilever deflections. Thus, the cantilever tip can be used to image live cells with atomic resolution and to probe single molecular events in living cells under physiological conditions. Currently, this is the only technique available that directly provides structural, mechanical, and functional information at high resolution. This unit presents the basic AFM components, modes of operation, useful tips for sample preparation, and a short review of AFM applications in microbiology.
