PNAS 1988-06-01

Specific and stable labeling of antibodies with technetium-99m with a diamide dithiolate chelating agent.

A R Fritzberg, P G Abrams, P L Beaumier, S Kasina, A C Morgan, T N Rao, J M Reno, J A Sanderson, A Srinivasan, D S Wilbur

Index: Proc. Natl. Acad. Sci. U. S. A. 85(11) , 4025-9, (1988)

Full Text: HTML

Abstract

Technetium-99m labeling of antibodies has been suboptimal because of low affinity adventitious binding, nonspecific labeling, and loss of immunoreactivity. The diamide dithiolate ligand system (N2S2) forms highly stable, well-defined tetradentate complexes with Tc(V). Antibodies and their fragments have been labeled by conjugation of preformed 99mTc-4,5-bis(thioacetamido)pentanoate active ester to protein amine groups to give a chemically known 99mTc-N2S2 complex covalently linked to antibody. Evaluations of the 99mTc-N2S2-bound antibodies and their fragments have shown high stability and retained immunoreactivity.