A novel cost-effective approach for the efficient radiolabeling of dendritic macromolecules with a β-emitting radiotracer

We describe herein a novel method for the radiolabeling of macromolecules containing primary amine groups. The method utilises radiolabeled acetic acid and exploits commonly used coupling chemistry for conjugation to primary amines in aqueous conditions. The method is a simple, cost-effective, and efficient approach for the small-scale radiolabeling of macromolecules overcoming the many issues of instability when using acetic anhydride as the radiolabeling agent. The use of radiolabeled acetic acid also provides for labeling at a relatively higher specific activity compared to that using acetic anhydride.