Chelating ion-exchange methods for the preparation of no-carrier-added 64Cu

Introduction We have developed a method for producing no-carrier-added 64 Cu by using chelating resin bearing iminodiacetic acid groups. Methods We optimized the conditions for the selective separation of radioactive Cu from Ni and Co using the chelating resin and produced no-carrier-added 64 Cu under the optimized conditions. We analyzed the amounts of the metal ions present in 64 Cu by inductively coupled-plasma mass spectroscopy (ICP-MS) and optical emission spectroscopy (ICP-OES), and performed radiolabeling of monoclonal antibodies in order to investigate the quality of the 64 Cu produced in this study. Results Radioactive Cu was separated from Ni and Co with 0.1 and 2 M HCl solutions. The yield of 64 Cu isolated from the 64 NiO target was almost 87%. The radiochemical purity of 64 Cu obtained from different amounts of 64 NiO targets was >99% in all cases. We found that the 64 Cu solution presented extremely low amounts of the metal ions and showed high specific activity (average: 595 GBq/μmol). Moreover, the antibodies were labeled with 64 Cu with a high average efficiency (average: 88%). Conclusions We could efficiently separate 64 Cu by using short ion-exchange columns. The chelating ion-exchange method provides a high quality of 64 Cu that is sufficient for the synthesis of 64 Cu-labeled antibodies and medical applications.