Atomic force microscopy (AFM) and surface plasmon resonance (SPR) are two important techniques to study the interaction between biomolecules under physiological conditions. AFM can be used to visualize these interactions and to measure forces between investigated molecules, whereas SPR provides information about binding affinities and kinetic parameters. In this work, AFM and SPR were applied on two different biological systems, both playing an important role in signal transduction processes in living cells.