Objective:To establish a double antibody sandwich ELISA assay for detection of human IL-37 in serum.Methods: Mouse anti-human IL-37 monoclonal antibody was used as capturing antibody,rabbit anti-human IL-37 polyclonal antibodies served as detection antibody,HRP labeled goat anti-rabbit IgG employed as second antibody and recombinant human IL-37 protein used as reference standard for the establishment of a doubleantibody sandwich ELISA.The working conditions were optimized,such as sensitivity,linear range,reproducibility and evaluated the serum IL-37 in patients with Dengue fever.Results: The sensitivity of the established ELISA method was 1.465 μg/L approximately.Likewise,the linearity range of this method was about (1.465-46.875) μg/L.Further,the co efficient of variation (CV) of inter-batch and intra-batch in this study were 6.6％ and 11.7％,respectively.Notably,this method could be used in the detection of IL-37 in serum of the patients with Dengue fever,showing that the level of IL-37 in Dengue fever patients was much higher than that in healthy controls.Conclusion: The double antibody sandwich ELISA assay for the detection of human IL-37 was successfully established,which can be apply to detect of human IL-37 in clinical samples.

We expressed B cell epitopes of dengue virus envelope protein and NS1 protein in prokaryotic cells,and purified and evaluated for its serological activities.A recombinant multi-epitope chimeric gene named rE including eight B cell epitopes was connected by linker peptide (EAAAK)2 and cloned into prokaryotic expression vector pET-28a(+),and transformed into E.coli BL21(DE3) cells for expression under induction of IPTG.The expressed recombinant protein was purified with 6× His purification media,and identified by SDS-PAGE and Western blot,and its antigenicity was analyzed by using an indirect ELISA assay.The recombinant expression vector pET28a-rE was constructed and expressed in BL21 (DE3) successfully,but the recombinant proteins mainly appeared as inclusion bodies.The target protein was obtained with high purity through the purification of affinity chromatography.SDS-PAGE and Western blot analysis showed that the molecular weight of fusion protein was in the expected line.The established indirect ELISA has high accuracy.This recombinant peptide antigen expressed in E.coli has good potential for serum testing.