ObjectiveTo express bovine interferon-γ (BovIFN-γ) in E.coli, and preliminarily identify its biological activity. MethodsAccording to the gene sequence in GenBank to construct the BovIFN-γ gene, and use it as the template, to amplify the BovIFN-γ gene by polymerase chain reaction (PCR). To insert the BovIFN-γ gene into vector PET-28a, transform it into E.coli BL21-competent cells, induce it with IPTG to express BovIFN-γ, and analyze it by Western blot. Using the NI-NTA affinity chromatography and electroelution to purify the recombination protein, and detect the protein antigenicity by commercial BovIFN-γ kit. ResultsThe recombinant plasmid PET-28a-BIFN-γ was successfully constructed, and BovIFN-γ was efficiently expressed in E.coli. The protein expression accounted for 32% of the total soluble bacterial proteins. The expression products mainly existed in soluble form in the cell lysate supernatant, and the proteion could be discriminated by BovIFN-γmonoclonal antibody. The recombinant protein purified by NI-NTA affinity chromatography had higher antigen activity than that by electroelution. ConclusionsThe soluble recombinant BovIFN-γ protein is successfully expressed in E.coli, and the protein can react with BovIFN-γ monoclonal antibody. The purified recombinant BovIFN-γ protein has good antigenicity.