Optimized indirect Br-76-bromination of antibodies using N-succinimidyl para-[Br-76]bromobenzoate for radioimmuno PET

Monoclonal antibody 38S1 was radiobrominated with the positron emitter Br-7 6 (T-1/2 - 16.2 h). Indirect labeling was performed using N-succinimidyl pa ra (tri-methylstannyl) benzoate (SPMB) as the precursor molecule. SPMB was labeled using Chloramine-T yielding N-succinimidyl para-[Br-76]bromobenzoat e, which was then conjugated to the antibody. Optimization of the labeling conditions and further conjugation gave a total yield (mean +/- max error) of 49 +/- 2%. The immunoreactivity of the antibodies was retained after lab eling. Thus, antibodies intended for positron emission tomography can be la beled with Br-76, which gives high yields and preserved immunoreactivity wh en using the SPMB technique described. NUCL MED BIOL 27;8:837-843, 2000. (C ) 2000 Elsevier Science Inc. All rights reserved.