Optimized AFM approaches for force indentation measurements associated with cell elasticity Elastizität Mechanik Zelle Rasterkraftmikroskopie Zellmechanik Kontaktmodell cell mechanics contact model atomic force microscopy The Atomic Force Microscope (AFM) has become an important tool for probing the mechanical properties of cells and microparticles by force indentation experiments. In this thesis optimized AFM approaches for these experiments are developed and applied to three types of living human cells in order to answer biologically relevant questions about their mechanics. These microscopic investigations are then interpreted with respect to nanoscopic and macroscopic biologic parameters such as the function of cell surface receptors or the size of human heart ventricles. This thesis comprises two physical technical chapters and three medical biological chapters. The physical technical chapters discuss the measurement process itself aiming for its improvement with respect to a proper data analysis and contact model (for spherical cells). The medical biological chapters investigate the elasticity of cells by the use of optimized AFM approaches with respect to the used data analysis.