Abstract: 【Objective】 Duck plague（DP） is an acute, septic contagion, caused by duck plague virus（DPV）, with the characteristics of head and neck swelling, the mucosa of esophageal and cloacal bleeding and yellowish-white ulcer, head and neck skin has a yellowish-white gelatin sample. Once an outbreak of this disease manifested by with high morbidity and high mortality, it would cause serious harm to the duck industry. The aim of this assay is to establish a method of colloidal gold strip for the detection of duck plague virus (DPV) rapidly. 【Method】 The main antigenic domain of DPV was chosen and analyzed by using of the Protean Biology software to design a pair of primer to amplify the aim gene by PCR. Then the fragment was inserted into prokaryotic expression vector pET-28a to construct recombinant plasmid. Then it was transformed into Rosetta for expression. During the experiment, the authors have groped the concentration of the IPTG and the induction time. After purification, the concentration of the aim protein was tested and was also analyzed and identified by Western blotting. Hybridoma cell lines stably secreting monoclonal antibody against gB protein of DPV were generated by fusing SP2/0 myeloma cells with splenocytes from the immunized mice, which used the gB protein of DPV, expressed and purified with prokaryotic, as the antigen. The monoclonal antibody-based colloidal gold immunochromatography strip was developed for the detection of DPV. The purified DPV-gB monoclonal antibody, named H6F6, was labeled with colloidal gold, with the appropriate pH between 8.0 and 8.5 and the concentration was 15 times dilution. The purified A8D7 monoclonal antibody, with the concentration of twice dilution, and the goat anti-mouse immunoglobulin G (IgG) antibody, with the concentration of ten times dilution, were blotted on nitrocellulose membrane as test line and control line, respectively. 【Result】 Hybridoma cell lines designated as A8D9, E6C3, H11F8, H6A10, stably secreting monoclonal antibody against gB protein of DPV. The titres of ascitic fluid was1:10³, 1:10³, 1:10⁵, 1:10³, respectively by indirect ELISA and the immunoglobulin subtype of the monoclonal antibodies was IgG2b, IgG2a, IgG2b, IgG1,with the light chain of kappa. The result of western blot showed that the four monoclonal antibodies were able to specifically recognize gB protein of DPV. The result of IFA showed that the four monoclonal antibodies were specific to DPV. The detection results indicated that the strip was specific to DPV and had no cross reaction with DRV, EDS-76V, AIV-H9N2, and TMUV. The detection limit of DPV were 50 times dilution. 38 clinical suspected samples were simultaneously detected by immunochromatography strip and PCR while the results showed 91.6 % accuracy between them. The monoclonal antibodies-based colloidal gold strip was highly specific and sensitive and more convenient for the clinical diagnosis of DPV.【Conclusion】The colloidal gold strip was highly specific and sensitive and more convenient for the clinical diagnosis of DPV.

Key words: duck plague virus, glycoprotein B, Prokaryotic expression, monoclonal antibody, colloidal gold strip