Nuclear magnetic resonance scanners, as are familiar from hospitals, are now extremely sensitive. A quantum sensor developed by a team headed by Professor Jörg Wrachtrup at the University of Stuttgart and researchers at the Max Planck Institute for Solid State Research in Stuttgart, now makes it possible to use nuclear magnetic resonance scanning to even investigate the structure of individual proteins atom by atom. In the future, the method could help to diagnose diseases at an early stage by detecting the first defective proteins.