Recombinant SARS N Protein Can React Specifically with SARS Patient's Serum

N protein is a nucleocapsid protein encoded by SARS CoV genome,which is different from any other known protein.Profound studies about it would conduce to elucidate the pathologic mechanism of SARS and develop the effective vaccine against it.Reverse transcription of dead virus was carried out,followed by PCR amplification with primer derived from the known local bases,and DNA sequencing of which proves the same results with published DNA sequence coding 422 amino acid residues.Then,N gene was cloned into prokaryotic expression vector pET28a,and transformed into E.coli BL21(DE3).Induced by IPTG,N protein was further purified by Ni 2+ chelating chromatography.The product was successfully used to find the specific antibody against N protein in SARS patients by Western blot and ELISA analysis,which provides a new method to diagnose the serious diseases and paves the way to develop a new vaccine against it.