Molecular Imaging and Contrast Agent Database (MICAD, USA)
Radiosynthesis Database of PET Probes (RaDaP, Japan)
Molecular Probe Library (NIRS, Japan)
18F-Database of Imaging Radiolabelled Compounds (DIRAC, France)
Chemical Entities of Biological Interest (ChEBI) (European Bioinformatics Institute (EMBL-EBI), UK)