The Analytics Core Facility Essen (ACE) is a central facility of the Center of Medical Biotechnology (ZMB) and of the Faculty of Biology of the University Duisburg-Essen. It offers access to state-of-the-art mass spectrometry-based proteomics for internal and external users. The timely technical equipment of the ACE allows us to provide a wide variety of different “bottom-up” and “top-down” proteomics methods. Furthermore, we also develop innovative solutions for project-specific demands. The service comprises all aspects of mass spectrometry-based proteomics, starting from technical advice and project planning, sample preparation and analysis to data analysis, data management and interpretation of results. We are also listed in the RIsources Poral of the DFG (RI_00466).