High efficiency iodination of monoclonal antibodies for radiotherapy.

A technique for labeling monoclonal antibodies (MoAb) with large activities of radioiodine using the reagent N-bromosuccinimide is described. This technique has been used to label three tumor-associated antibodies with an average labeling efficiency of greater than 90%. No significant damage to the antibody could be detected by enzyme linked immunosorbent assay (ELISA), performed immediately after the labeling procedure. Because high radiochemical purity can be achieved without the need postlabeling purification, the procedure is rapid and results in very low radiation doses to staff.