Simple and rapid methods for labelling of human IgG by four radionuclides

Labelling of DTPA bicyclic anhydride coupled antibodies were investigated by determining the effect of DTPA: antibodies, DTPA: Sn molar ratios, pH, dimer and polymer formation of antibodies coupled with DTPA, using three different radionuclides, [¹¹¹In,⁹⁰Y and^99mTc]. Analyses were performed with by Whatman No. 1 paper strips. Under optimal conditions we have achieved specific activities of¹¹¹In or⁹⁰Y labelled antibodies of about 37 kBq/1 g for IgG coupled with about 2 DTPA groups per molecule and protein concentration of 15 mg/ml.