High yield direct 76Br-bromination of monoclonal antibodies using chloramine-T.
Monoclonal antibody (MAb) A33 was labeled with the positron emitter 76Br (T(1/2) = 16.2 h). Direct labeling was done using the conventional chloramine-T method. After optimization of the labeling conditions, a maximum yield (mean +/- max error) of 77 +/- 2% was obtained at pH 6.8. In vitro binding of 76Br-A33 to SW1222 colonic cancer cells showed that the immunoreactivity was retained. Also, the MAbs 38S1 and 3S193 and the peptide hEGF were 76Br-labeled, resulting in labeling yields (mean +/- max error) of 75 +/- 3%, 63 +/- 4%, and 73 +/- 0.1%, respectively. We conclude that antibodies and peptides can be labeled conveniently with 76Br for the purpose of whole-body tumour imaging by positron emission tomography.
Sundin
J
J
Department of Oncology, Radiology and Clinical Immunology, Uppsala University, Sweden. Johanna.Sundin@pet.uu.se
Tolmachev
V
V
Koziorowski
J
J
Carlsson
J
J
Lundqvist
H
H
Welt
S
S
Larson
S
S
Sundin
A
A
D000911:Antibodies, Monoclonal / Q000737:chemistry* / Q000276:immunology; D001967:Bromine Radioisotopes; D002021:Buffers; D002700:Chloramines / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007150:Immunohistochemistry; D007202:Indicators and Reagents; D007553:Isotope Labeling; D019275:Radiopharmaceuticals / Q000138:chemical synthesis*; D014105:Tosyl Compounds / Q000737:chemistry*; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D001967:Bromine Radioisotopes; D002021:Buffers; D002700:Chloramines; D007202:Indicators and Reagents; D019275:Radiopharmaceuticals; D014105:Tosyl Compounds; C016300:chloramine-T