An optimized antibody-chelator conjugate for imaging of carcinoembryonic antigen with indium-111.
A monoclonal antibody to carcinoembryonic antigen showing minimal cross-reactivity with blood cells and normal tissues was derivatized with benzylisothiocyanate derivatives of EDTA and DTPA. Seven chelators per immunoglobulin could be incorporated without loss of immunoreactivity. The resulting conjugates, labeled with indium-111, showed low liver uptake in animals. A cold kit, comprising the DTPA conjugate at a molarity of antibody bound chelator exceeding 1 x 10(-4) M, gave radiochemical yields of indium labeled antibody of greater than or equal to 95% and was stable for 1 yr.
Sumerdon
G A
GA
Abbott Laboratories, Abbott Park, IL 60064.
Rogers
P E
PE
Lombardo
C M
CM
Schnobrich
K E
KE
Melvin
S L
SL
Hobart
E D
ED
Tribby
I I
II
Stroupe
S D
SD
Johnson
D K
DK
D000818:Animals; D000911:Antibodies, Monoclonal; D002272:Carcinoembryonic Antigen / Q000276:immunology*; D002614:Chelating Agents; D003110:Colonic Neoplasms / Q000000981:diagnostic imaging / Q000276:immunology; D005260:Female; D006801:Humans; D007205:Indium Radioisotopes; D007553:Isotope Labeling / Q000379:methods; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging / Q000276:immunology; D011877:Radionuclide Imaging; D014183:Transplantation, Heterologous
D000911:Antibodies, Monoclonal; D002272:Carcinoembryonic Antigen; D002614:Chelating Agents; D007205:Indium Radioisotopes