Abstract: Objective:To express and purify VASN-EGFFNN3 recombinant protein by Escherichia coli(E.coli-)expression system and immunize mice to prepare anti-VASN-EGFFNN3 mAb.Methods:A pET30a(+)-VASNEGFFNN3 recombinant vector was constructed. E.coli BL21(DE3) was used as the vector to express VASNEGFFNN3 recombinant protein.The VASN-EGFFNN3 recombinant protein was purified by nickel ion(Ni)affinity chromatography column.After immunizing BALB/c mice with purified VASN-EGFFN3 recombinant protein, anti-VASN-EgffN3 monoclonal antibody was prepared by hybridoma technique.Results:A pET30a(+)-VASNEGFFNN3 recombinant prokaryotic expression plasmid was successfully constructed.The induced recombinant VASN-EGFFNN3 protein mainly existed in the form of inclusion bodies.The antibody titer of serum obtained from BALB/c mice immunized with the purified protein was tested greater than 1:2187000, indicating a good immune effect.Two hybridoma cell lines were obtained using hybridoma technique.Conclusion:The VASN-EGFFNN3 recombinant protein is successfully prepared and purified by using E.coli expression system and the mouse anti-VASN-EGFFN3 monoclonal antibody is successfully prepared by hybridoma technology.