A separation method will be tested and evaluated to determine the feasibility of providing no carrier added lutetium-177 (Lu-177) for use in radiotherapeutic applications. An indirect method will be used to produce Lu-177 (neutron capture followed by decay). Separation of the Lu-177 from the target material will enable us to provide carrier-free Lu-177 suitable for therapeutic applications. Phase I of this project will entail developing a separation method for isolating nanogram amounts of Lu-177 from macroscopic amounts of ytterbium (Yb) and evaluating if the Lu-177 produced can then be attached to biomolecuies for radioimmunotherapy. Phase II will involve scale-up of the method and development of target recovery techniques, remote processes for hot cell production and quality control methods to manufacture the Curie quantities needed for medical applications. Specific Aim 1: Determine if a reduction separation technique can be used to isolate nanogram quantities of Lu-177 from macroscopic amounts of Yb, thereby providing carrier-free (high specific activity) Lu-177. Specific Aim 2: Evaluate the Lu-177 produced for metal impurities that might be introduced during the process that could interfere with attaching the radioisotope to molecules of interest in radiotherapeutic applications. If impurities are present, develop methods to prevent their introduction or to remove them from the final product. Perform radiolabelling of the Lu-177 produced to molecules of interest in therapeutic applications.