99mTc direct labeling of anti-CEA monoclonal antibodies: quality control and preclinical studies.
The anti-carcinoembryonic B2C114 monoclonal antibody was radiolabeled with 99mTc by a direct method and quality control tested in vitro by instant thin layer chromatography, gel column scanning and cellulose acetate electrophoresis and assessed in vivo for radioimmunodetection on a murine spontaneous mammary carcinoma. The optimal results of percent 99mTc bound to protein were obtained at a dithiothreitol:antibody molar ratio ranging from 800:1 to 1000:1 and at a methylene diphosphonate:stannous fluoride weight ratio of 4.3:1. Although cysteine removed up to 18% of the label during the first 4 h, the stability of the tracer appeared to be excellent in human serum at 37 degrees C and when challenged with DTPA. 99mTc-labeled B2C114 demonstrated good and specific in vivo tumor targeting.
De Castiglia
S G
SG
Oncologic Center of Nuclear Medicine, National Atomic Energy Commission, Buenos Aires, Argentina.
Duran
A
A
Fiszman
G
G
Horenstein
A L
AL
D000818:Animals; D000911:Antibodies, Monoclonal / Q000493:pharmacokinetics; D002272:Carcinoembryonic Antigen / Q000276:immunology; D006801:Humans; D007553:Isotope Labeling / Q000379:methods / Q000592:standards*; D008325:Mammary Neoplasms, Experimental / Q000175:diagnosis / Q000000981:diagnostic imaging*; D051379:Mice; D008807:Mice, Inbred BALB C; D015609:Organotechnetium Compounds; D011786:Quality Control; D011877:Radionuclide Imaging; D014018:Tissue Distribution
D000911:Antibodies, Monoclonal; D002272:Carcinoembryonic Antigen; D015609:Organotechnetium Compounds