Correlation of immunoreactivity and polymer formation to DTPA modification of a monoclonal antibody.
The protocol used for coupling of monoclonal antibodies with mixed anhydride of DTPA for subsequent radiolabeling with indium-111 affects the integrity of the immunoreactivity of the antibody preparations. To analyze the effect of minor methodological variations on coupling characteristics, a two-step addition of DTPA to antimyosin antibody with gentle mixing was compared to a single addition with vigorous stirring. The molar ratios of DTPA to antibody were also varied. The polymer formation was assessed by SDS-PAGE and immunoreactivity was assessed by solid phase radioimmunoassay using human heart myosin as the antigen. The immunoreactivity was significantly decreased in the two-step, gentle-mixing method where polymer formation was evident. The one-step, vigorous-stirring method of DTPA incorporation produced no polymerization and no loss of immunoreactivity.
Yin
O
O
Division of Nuclear Medicine, Massachusetts General Hospital, Boston 02114.
Narula
J
J
Nossiff
N
N
Khaw
B A
BA
D000911:Antibodies, Monoclonal / Q000737:chemistry* / Q000276:immunology; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D007205:Indium Radioisotopes; D009206:Myocardium / Q000276:immunology; D009218:Myosins / Q000276:immunology; D004369:Pentetic Acid / Q000737:chemistry* / Q000276:immunology; D011108:Polymers; D011863:Radioimmunoassay
D000911:Antibodies, Monoclonal; D007074:Immunoglobulin G; D007205:Indium Radioisotopes; D011108:Polymers; D004369:Pentetic Acid; D009218:Myosins