[The Preparation of Epitope-based Recombinant Rubella Virus Diagnostic Antigen]

To prepare an epitope-based recombinant Rubella virus (RV) recombinant diagnostic antigen(designated ‘H29’) and preliminarily evaluate its antigenicity. With Glutathione S-Transferase (GST) located at the N-terminal, and the His tag at the C-terminal, the epitope-based RV recombinant diagnostic antigen (designated‘H29’) was expressed in Escherichia coli (E.coli) and purified by affinity and anion exchange chromatography. Based on the antigenicity of H29 identified by Western blot (WB), we constructed and evaluated a novel early diagnostic ELISA for RV infection. The soluble H29 protein with a high homogeneity was obtained; the WB analysis demonstrated that the H29 protein could bind to a monoclonal antibody for RV-E1 and GST antigens, as well as detect RV acute-phase serum. Using the novel ELISA, the serum from 48 cases with positive RV infection,48 cases with negative RV infection, and 48 healthy people was detected, displaying the excellent consistency. Using prokaryotic expression and chromatography purification, the epitope-based recombinant RV-IgM diagnostic antigen was obtained with excellent antigenicity, which could be applied for the serological detection of the early infection with RV.