Objective To induce expression of nucleoprotein gene of Sendai virus (SV) in prokaryotic system. MethodsA pair of primers were designed and synthesized according to the SV nucleoprotein gene sequence published by GenBank. Nucleoprotein gene was amplified by RT-PCR. Recombinant pET-SN was constructed after the SN gene was sequenced. BL21(DE_3)pLysS was induced with 1 mmol/L IPTG. ResultsSDS-PAGE showed that the recombinant protein was about 60 Ku which could react with rabbit-anti Sendai virus serum in Western blot assay. ConclusionThe recombinant nucleoprotein as an antigen may provide a basis for diagnosis of Sendai virus.