Preparation of monoclonal antibody against human insulin-like growth factor-1 (hIGF-1) protein in E.Coli

Objective To express human insulin-like growth factor-1(hIGF-1) and produce mouse monoclonal antibody(mAb) against the protein.Methods By PCR technique,the target gene was amplified from human live cDNA and then inserted into the expression vector pET28a(+).The recombinant vector pET-28a(+) /hIGF-I was expressed in E.coli BL21 after induced by IPTG.The purified recombinant protein was used to immunize BALB /c mouse.The specificity of mAb was analyzed by ELISA and western blot.Results hIGF-I protein was successfully expressed and purified.SDS-PAGE analysis showed that the molecular weight of the expressed protein was approximately 18 KD.One hybridoma cell(8F2)secreting mAb against hIGF-1 was developed.The isotype of the mAb was IgG2 b.ELISA detection showed that titers of mAb was 1 ∶7.5× 105 in ascites.Western blot analysis proved mAb obtained could react specifically to the recombinant hIGF-1protein,and mAbs were successfully prepared.Conclusions Recombinant hIGF-I protein and mAb against hIGF-I were successfully prepared which might be helpful for tumor treatment.