Objective: To prepare monoclonal antibodies (mAbs) against human fibroblast growth factor 21 (hFGF-21), and identify the epitope of hFGF-21 mAb through bacterial display.
Methods: With hFGF-21 as an immunogen and detective antigen, we screened hybridoma cell lines secreting anti-hFGF-21 mAbs using indirect ELISA. The different fragments of hFGF-21 were cloned into bacterial display vector (Apex) to identify the epitope by fluorescence-activated cell sorting (FACS) using FITC-labeled mAbs.
Results: We obtained a stable hybridoma cell line secreting mAbs against hFGF-21; the heavy and light chains of the mAb were IgG 2b and Kappa, respectively. The ascites titer of the hybridoma cell line was 1:4.096×10(6);. The cell line was stable after 30 passages or when stored in liquid nitrogen for 3 months. Western blotting showed the mAbs could bind to hFGF-21 specifically, and could cross-react with murine FGF-21. FACS indicated that this antibody could bind to downstream 107-121 amino acids of hFGF-21.
Conclusion: The mAbs against hFGF-21 we prepared showed high specificity and stability; the epitope of the mAbs was 107-121 amino acids of hFGF-21.