Preparation of a pure 99mTc-F(ab')2 radioimmunoconjugate by direct labeling methods.
Intact IgG and Fab' can be labeled directly with 99mTc to give quantitative incorporation of radioactivity into the protein. With F(ab')2 the reductive conditions yield a mixture of 99mTc-F(ab')2 and 99mTc-Fab'. We now report a direct labeling method to produce only 99mTc-F(ab')2 in quantitative yield and contaminated with 99mTc-Fab'. The properties, stability and biodistribution of the 99mTc-F(ab')2 have been compared to 99mTc-Fab'. This new technology will allow us to compare technetium direct-labeled IgG, F(ab')2 and Fab' derivatives of the same antibody for radioimmunodetection.
Griffiths
G L
GL
Immunomedics Inc., Morris Plains, NJ 07950, USA.
Goldenberg
D M
DM
Jones
A L
AL
Hansen
H J
HJ
D000818:Animals; D003110:Colonic Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism; D005260:Female; D006801:Humans; D018796:Immunoconjugates / Q000737:chemistry* / Q000493:pharmacokinetics; D007140:Immunoglobulin Fab Fragments / Q000737:chemistry* / Q000378:metabolism; D007553:Isotope Labeling / Q000379:methods*; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000138:chemical synthesis* / Q000493:pharmacokinetics; D017556:Technetium Compounds / Q000138:chemical synthesis* / Q000493:pharmacokinetics; D014018:Tissue Distribution
D018796:Immunoconjugates; D007140:Immunoglobulin Fab Fragments; D019275:Radiopharmaceuticals; D017556:Technetium Compounds