文摘
Today the main radionuclide used for preparing radiopharmaceuticals throughout the world is 99m Tc, thanks to its optimal nuclear-physical characteristics and ready availability. Several approaches are used for tethering this radionuclide to biomolecules (peptides, antibodies, etc.); one of them involves the use of so-called bifunctional chelating agents (BCAs). These compounds are capable both of binding 99m Tc and of linking to biomolecules. Today the most frequently used BCAs are DTPA, MAG3, and HYNIC. These BCAs are described and compared. The peptides that are most frequently used in combination with these agents are described and compared. Published data on the choice of a coligand for use in combination with HYNIC are discussed.