A new method has been developed for conjugating @entity5531 ( @entity12306 ) to proteins using the @entity14314 active @entity13507 of @entity12306 . The @entity12306 -active @entity13507 was prepared using @entity28769 in a simple single step synthesis. @entity12306 -conjugated proteins were prepared by adding the @entity12306 -active @entity13507 reaction mixture to protein solutions (5 mg/ml) buffered at pH 7.0 and purified by Sephadex G-50 chromatography. A monoclonal antibody directed against carcinoembryonic antigen was reacted with four different amounts of the @entity12306 -active @entity13507 . Solid-phase enzyme immunoassay showed that the immunological activity of the antibody conjugate was not altered when the active @entity13507 : antibody molar ratio was 36:1 or 72:1; however, it decreased when the ratio was 180:1 or 360:1. The antibody heavy and light chains had slightly decreased electrophoretic mobilities when analyzed by @entity3208 - @entity2975 gel electrophoresis, a result consistent with the covalent attachment of @entity12306 to the protein. Sephadex G-200 chromatography showed that the native and conjugated antibodies were the same size. When the @entity12306 -conjugated antibody was incubated with 10, 50, and 100 microCi of 111In/micrograms of protein, specific activities of 9.8, 43.1, and 56.3 microCi/micrograms were obtained. Enzyme immunoassay and radioimmunoassay of the 111In-labeled antibody showed that it retained its full immunological activity. The high specific activity of the 111In-labeled antibody makes it suitable for imaging @entity5 using low doses of antibody.

High-specific-activity 111In-labeled anticarcinoembryonic antigen monoclonal antibody: improved method for the synthesis of XXXX conjugates.

@entity3208 :: ('MESH:D012967', 'Chemical') :: ['sodium dodecyl sulfate'] @entity5 :: ('MESH:D009369', 'Disease') :: ['carcinoembryonic antigen-bearing tumors'] @entity28769 :: ('CHEBI:53092', 'Chemical') :: ['diisopropylcarbodiimide'] @entity2975 :: ('CHEBI:51135', 'Chemical') :: ['polyacrylamide'] @entity14314 :: ('MESH:C001426', 'Chemical') :: ['N-hydroxysuccinimide'] @entity5531 :: ('MESH:D004369', 'Chemical') :: ['diethylenetriaminepentaacetic acid'] @entity13507 :: ('CHEBI:35701', 'Chemical') :: ['ester'] @entity12306 :: ('MESH:C028145|MESH:D004369', 'Chemical') :: ['DTPA']
@entity5531 :: (MESH:D004369,Chemical) :: ['diethylenetriaminepentaacetic acid']
