Direct 99mTc labeling of monoclonal antibodies: evaluation of reducing agents and HPLC analysis

• Published in: Journal of labelled compounds & radiopharmaceuticals Vol. 41; no. 1; pp. 37 - 45
• Main Authors: Liu, Ning, Jin, Jiannan, Mo, Shangwu, Chen, Hengliu, Yu, Yanping, Xu, Bingxun, Chen, Qi
• Format: Journal Article
• Language: English
• Published: Chichester John Wiley & Sons, Ltd 01.01.1998; Wiley
• Subjects: 99mTc; Analytical, structural and metabolic biochemistry; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Glycoproteins; HPLC; IgG; Labeling method; Monoclonal antibody; Proteins; Stability; Human; Chemical reduction; Ascorbic acid; Stability; Radiolabelling; IgG; Glycoproteins; Monoclonal antibody; Technetium Isotopes; Protein
• ISSN: 0362-4803; 1099-1344
• DOI: 10.1002/(SICI)1099-1344(199801)41:1<37::AID-JLCR51>3.0.CO;2-G

Human IgG was used as a model antibody and the results for direct 99mTc labeling of IgG using 2‐mercaptoethanol (2‐ME), dithiothreitol (DTT) and ascorbin acid (AA) as reducing agents were evaluated. DTT was chosen as reducing agent and an intact monoclonal antibody 3H11 was labeled with 99mTc with a labeling yield of more than 98% while its Fab fragment was labeled with 99mTc in less than 35% yield. The 99mTc labeled antibodies were analysed by HPLC on a size exclusion column with an eluent of 0.1 mol/L PBS(pH 7.0), and the in vitro stability of 99mTc‐3H11 was investigated. HPLC analysis revealed that 99mTc‐3H11 Fab is not in a singular structure, and the procedure for direct 99mTc labeling of antibody's Fab Fragment should be further investigated. © 1998 John Wiley & Sons, Ltd.