Research at the Max Planck Institute for Medical Research has, ever since its founding in 1927 as a Kaiser Wilhelm Institute, benefited from the work of notable scientists and excellent science on the border between physiology, physics, chemistry and biology. With the appointment of three new directors in the last few years, the institute has experienced a major reorientation. The new, central topic of research is to observe in real time and manipulate the complex dynamics of the interactions between macromolecules in the living cell, in health and disease. The four departments contribute their unique expertise in complementary areas: the determination of atomic structures (Ilme Schlichting), optical nanoscopy (Stefan Hell), design of new reporter molecules (Kai Johnsson) and cellular material research and biophysics (Joachim Spatz). This involves developing tools for biomedical research which could lead to new knowledge, insights and medical advances. In doing this, the institute upholds the vision of the founder, Ludolf von Krehl, to advance medical research through the collaboration of physiology, biology, physics and chemistry under one roof. Imprint: https://www.mr.mpg.de/imprint