Abstract
This chapter aims to introduce the molecular players involved in cell adhesion and to describe the particular application of the atomic force microscope to study the behaviour of the peculiar proteins under force. Different configurations can be adopted to probe cell adhesion at the single-molecule level. Cell adhesion is involved in the formation and the functional and structural integrity of multicellular organisms. Cell adhesion molecules (CAMs) connect cells to each other and to the extracellular matrix mediating intercellular communication and providing mechanical stability. Specificity is accomplished by expressing particular types of CAMs that recognize specific ligands. The adhesive capacity of cells depends not only on the adhesion strength of individual CAMs, but also on other factors including the mechanical properties of the cell, its activation state, the biochemical microenvironment and the distribution and expression level of receptors and ligands.