PURIFICATION OF RADIOLABELED MONOCLONAL-ANTIBODIES TO ANGIOTENSIN-CONVERTING ENZYME SIGNIFICANTLY IMPROVES SPECIFICITY AND EFFICACY OF ITS TARGETING INTO THE LUNG

The aim of this study was to improve the labeling/purification procedu res for monoclonal antibody (MoAb) to angiotensin-converting enzyme (A CE). MoAb 9B9 was very stable upon iodination at a wide range of iodog en concentrations and incubation times, and was also very stable upon storage, indicating the high technological potential of this MoAb. Rad iolabeled MoAb 9B9 was purified by (i) adsorption chromatography on ce llulose, (ii) HPLC (gel filtration) and (iii) affinity chromatography on ACE-Sepharose. The best result was obtained with cellulose: specifi city of MoAb 9B9 accumulation in the lung increased 2-fold. We conclud e that the phenomenon of specific lung accumulation of MoAb 9B9 may se rve as an ideal (convenient, cheap and technological) assay system for evaluation of monoclonal antibody modification and labeling.