Preparation and identification of monoclonal antibody against human insulin-like growth factor-1

Objective:To establish the specific hybridoma cell lines that stably secreted monoclonal antibody(mAb) against human insulin-like growth factor-1 and identificate its properties. Methods:Balb/c mice were immunized with purified recombinant human IGF-1 protein. Splenocytes of the immunized mice were collected and fused with the mouse myeloma cell line Sp2/0 cells. The hybridoma cells that secreted human IGF-1 mAb were subcloned with limited dilution. The specificity of mAb was detected by Western blot. Indirect enzyme-linked immunosorbent assay(ELISA) was used to evaluate the affinity and titers of mAbs. The immunoglobulin (Ig) subtype of mAb was determined by test paper bar. Results:Two stably secreting anti-hIGF-1 mAb cell lines were obtained. Western blot analysis showed the mAb had specific combination with human IGF-1 which possessed biological activities. The titers of both mAb in ascites were 6 × 104 and their relative affinities were between 2.1 × 109/mol～7.8 × 109/mol. Two mAb cell lines can secret IgM subtype antibodies. Conclusion:Two hybridoma cell lines that secreted anti-hIGF-1 mAb were obtained,which will be useful for clinical application and fundamental basic research in hIGF-1.