DOTA

DOTA (tetraazacyclododecanetetraacetic acid) is a macrocyclic chelator widely used for coordinating metal ions in radiopharmaceuticals and targeted imaging agents. Its macrocyclic structure contains four nitrogen atoms and four carboxylate groups that form highly stable complexes with a variety of metal ions, including lanthanides and therapeutic radionuclides. This strong coordination chemistry enables reliable attachment of radioactive metals to biomolecules such as peptides, antibodies, or small molecules.