In vitro evaluation of concentration, labeling effectiveness and stability for ¹³¹I-labeled radioimmunoassay ligand using real-time detection technology

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• 作者：Pavel Barta ; Jiri Janousek ; Katerina Zilkova and Frantisek Trejtnar
• 刊名：Journal of Labelled Compounds and Radiopharmaceuticals
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：60
• 期：1
• 页码：80-86
• 全文大小：556K
• ISSN：1099-1344

文摘

Radioimmunoassay belongs to the analytical method enabling highly specific and sensitive quantification of molecules. The verification of the real-time radioimmunoassay technology usefulness for ligand-quality characteristics evaluation such as concentration, influence of radiolabeling on binding affinity and stability was estimated. The anti-epidermal growth factor receptor antibody ¹³¹I-cetuximab was employed as the ligand antibody. The concentration of ¹³¹I-cetuximab was derived from the shape of binding curves coming from the ligand-receptor interaction. The binding curves also allowed the estimation of ¹³¹I-cetuximab binding affinity for different radiolabeling procedures (incubation times 1, 5, and 10 minutes) in stability testing up to 96 hours at 4°C. The stability testing also included comparative analysis by size exclusion high-performance liquid chromatography. The assessment of cetuximab concentrations using real-time method showed acceptable accordance between real and calculated values. The real-time method revealed that 1-minute radiolabeling proved to be the optimal incubation time for direct radioiodination of cetuximab. Stability testing showed the significant change in radioligand affinity by one order at the longest incubation times (72 and 96 hours). Characterization of stability and binding behavior of radiolabeled monoclonal antibodies by the verified real-time method before use in other assays may be employed to eliminate variability and suboptimal antibody performance.