To date, examining patient tissue samples has meant cutting them into thin slices for histological analysis. This might now be set to change — thanks to a new staining method devised by an interdisciplinary team from the Technical University of Munich (TUM). This allows specialists to investigate three-dimensional tissue samples using the Nano-CT system also recently developed at TUM. Tissue sectioning is a routine procedure in hospitals, for instance to investigate tumors. As the name implies, it entails cutting samples of body tissue into thin slices, then staining them and examining them under a microscope. Medical professionals have long dreamt of the possibility of examining the entire, three-dimensional tissue sample and not just the individual slices. The most obvious way forward here lies in computed tomography (CT) scanning — also a standard method used in everyday clinical workflows. Today’s Micro- and Nano-CT systems are rarely suitable for use in frontline medicine. Some do not offer sufficiently high resolution, while others rely on radiation from large particle accelerators. Secondly, soft tissue is notoriously difficult to examine using CT equipment. Samples have to be stained to render them visible in the first place. Stains for CT scanning are sometimes highly toxic, and they are also extremely time-consuming to apply. Now, however, scientists at TUM’s Munich School of BioEngineering (MSB) have solved both problems. In November 2017, Prof. Franz Pfeiffer and his team unveiled a Nano-CT system that delivers resolutions of up to 100 nanometers and is suitable for use in typical laboratory settings. In the current issue of Proceedings of the National Academy of Sciences (PNAS), the cross-disciplinary research team from physics, chemistry and medicine also presents a staining method for histological examination with Nano-CT.