Measuring polysaccharide mechanics by atomic force microscopy

INTRODUCTIONPolysaccharides are frequently subjected to mechanical forces in vivo. Because these forces affect a wide range of biological activities, it is important to develop methods that directly investigate the mechanical properties of these molecules. Recent progress in techniques that allow the mechanical manipulation of biopolymers at a single-molecule level has revealed the complex nature of the elasticity of polysaccharides. The atomic force microscope (AFM) is an excellent force spectrometer for probing the mechanical properties (e.g., length and tension) of individual polysaccharides. The following protocol describes the use of AFM for stretch-release measurements of polysaccharide chains.