Used as a key reagent in bioconjugation, particularly for radiolabeling proteins and antibodies with iodine isotopes such as iodine-125 or iodine-131. Its active ester group reacts efficiently with primary amines on biomolecules, forming stable amide bonds, while the iodobenzoate moiety allows for subsequent radiolabeling or attachment to surfaces. Commonly applied in the development of diagnostic imaging agents, radioimmunoassays, and targeted radiotherapeutics. Also utilized in immobilizing biomolecules onto solid supports for biosensors and affinity chromatography due to its ability to link amine-containing compounds to functionalized surfaces.