Ubiquitin marks proteins for degradation, whereby ubiquitin molecules can be combined in different types and numbers forming different chains. Researchers at the Max Planck Institute of Biochemistry (MPIB) have developed the new UbiREAD technology to decode the various combinations of ubiquitin molecules – the ubiquitin code – which determine how proteins are degraded in cells. Using UbiREAD, scientists label fluorescent proteins with specific ubiquitin codes and track their degradation in cells. The study, published in Molecular Cell, revealed which Ubiquitin code can or cannot induce intracellular protein degradation.