A NEW METHOD OF TC-99M LABELING OF MONOCLONAL-ANTIBODIES THROUGH SUGAR RESIDUES - A STUDY WITH TAG-72 SPECIFIC CC-49 ANTIBODY

We have developed a very efficient labeling technique for monoclonal a ntibodies with technetium-99m. Oxidation of sugar residues on the IgG class of antibodies leads to the generation of aldehyde groups which a re further reacted with two newly developed hydrazide compounds. This methodology introduces sulfhydryl groups on the antibody through sugar residues which can be labeled with technetium-99m. We have studied th e TAG-72 specific second generation antibody CC-49. The specific activ ity of the labeled antibody was high without loss of its immunoreactiv ity.