DARU Journal of Pharmaceutical Sciences141A new monoclonal antibody radiopharmaceutical for radioimmunoscintigraphy of breast cancer: direct labeling of antibody and its quality control5156Mojtaba SaloutiHossein RajabiMohammad Hossein BabaeiMohammad Javad RasaeeReza NajafiMalihe PaknejadMohammad HasanTaghi. AltarihiJavad Mohammad Nejad20151006Radioimmunoscintigraphy (RIS) has found widespread clinical application in tumor diagnosis. The antibody (Ab) PR81 is a new murine anti-MUC1 monoclonal antibody (MAb) against human breast carcinoma. In this study a very simple, rapid and efficient method for labeling of this MAb with 99mTc, particularly suitable for development of a ‘kit’is described. The reduction of Ab was performed with 2-mercaptoethanol (2-ME) at a molar ratio of 2000:1 (2-ME:MAb) and the reduced Ab was labeled with 99mTc via methylene diphosphonate (MDP) as a transchelator. The labeling efficiency which was determined by instant thin layer chromatography (ITLC) was 94.2%±2.3. Radiocolloides measured by cellulose nitrate electrophoresis were 2.5%±1.7. In vitro stability of the labeled product in human serum which was measured by gel filtration chromatography (FPLC) was 70%±5.7 over 24 hr. The integrity of labeled MAb was checked by means of SDS-PAGE and no significant fragmentation was observed. The results of the cell-binding studies showed that both labeled and unlabeled PR81 were able to compete for binding to MCF 7 cells. Biodistribution studies were performed in normal BALB/c mice at 4 and 24 hrs post-injection and no important accumulation was observed in vital organs. These results show that the new radiopharmaceutical may be considered as a promising candidate for imaging of breast cancer.https://daru.tums.ac.ir/index.php/daru/article/view/264https://daru.tums.ac.ir/index.php/daru/article/download/264/264