Atomic force microscopy (AFM) is an indentation technique used to reconstruct the topography of various materials and organisms. AFM can also measure the mechanical properties of the sample. In plants, AFM is applied to image cell wall structural details and measure the elastic properties in the outer cell walls. Here, I describe the use of high-resolution AFM to measure the elasticity of resin-embedded ultrathin sections of leaf epidermal cell walls. This approach allows to access the fine details within the wall matrix and eliminate the influence of the topography or the turgor on mechanical measurements. In this chapter, the sample preparation, AFM image acquisition, and processing of force curves are described. Altogether, these methods allow to measure the wall stiffness and compare different cell wall regions.
Keywords: AFM; Anticlinal walls; Atomic force microscopy; Cell walls; Elastic modulus; Elasticity; Epidermis; Indentation; Pavement cells.