Objective:To prepare polyclonal antibody to recombinant mouse interleukin-27（IL-27）fusion protein and to detect its activity. Methods:Reverse transcription PCR was used to clone mature peptide gene fragments of EB virus induced gene 3（EBI3）and p28 from mouse spleen cells. Both fragments of EBI3 and p28 were joined together with（Gly4Ser）3using splicing overlap extension（SOE）PCR to obtain single-stranded IL-27 fusion gene fragment. Then

recombinant p ET32a（+）-IL-27 was prepared by inserting IL-27 fusion gene fragment into p ET32a（+）vector. Positive recombinant plasmid was transformed into Escherichia coli BL21（DE3）and fusion protein expression was induced by Isopropyl β-D-1-Thiogalactopyranoside（IPTG）. SDS-PAGE and Western blot were used to identify protein expression. Purified IL-27 fusion protein was used to immunize New Zealand rabbits to prepare polyclonal antibody. Titer and specificity of polyclonal antibody to IL-27 were analyzed by ELISA and Western blot respectively. Results:Singlestranded IL-27 fusion gene fragment was amplified

which sequence was consistent with the expected sequence. Western blot and SDS-PAGE showed that IL-27 fusion protein was successfully induced in Escherichia coli BL21（DE3）. Obtained serum can specifically recognize IL-27 fusion protein and titer of rabbit polyclonal antibody was about 1∶3 200. Conclusion:Recombinant mouse IL-27 fusion protein is successfully obtained and rabbit anti-IL-27 antibody with high titer and specificity is prepared.