76Br-labeled monoclonal anti-CEA antibodies for radioimmuno positron emission tomography

Abstract For the application of anti-tumor monoclonal antibodies (MAbs) in positron emission tomography (PET), labeling radionuclides with half-lives allowing a suitable time frame for imaging are required. The anti-CEA MAb 38S1 was labeled with the positron emitting nuclide 76 Br ( t 1 2 16 h ) using bromoperoxidase (BPO), and subsequently affinity purified. A procedure was devised to allow reproducible production of MAb-preparations of high immunoreactivity and with acceptable bromination yield. The biological activity of 76 Br-38S1 was retained and comparable to that of chloramine-T labeled 125 I-38S1, as tested in vitro .