Development of an immunochromatographic strip for rapid detection of antibodies against classical swine fever virus.
The genes encoding the Erns and E2 antigen epitopes of classical swine fever virus (CSFV) were expressed as a chimeric protein in Escherichia coli BL21 by pET expression system. The antigenicity of the expressed protein CnC2 was identified by indirect enzyme-linked immunoabsorbant assay (ELISA) and immunoblot with anti-CSFV antibodies. Based on the CnC2 protein, an immunochromatographic strip was developed to evaluate the antibody titer of serum samples from swine vaccinated with CSFV vaccine rapidly. The chimeric protein used as a detector was labeled with colloidal gold. Staphylococcal protein A (SPA) and anti-CnC2 monoclonal antibodies (mAbs) were blotted onto the nitrocellulose membrane as the test and control lines, respectively. The strip assay could be performed within 5min, which did not require any special equipment or skills. Through testing sera against various strains of CSFV, the sensitivity of the strip was determined to be 97.0% (65/67) and the specificity was 100% (98/98). The strip results were consistent with those of the existing commercial ELISA kit, and their correlation coefficient was 0.935. In conclusion, the immunochromatographic strip was an acceptable method for surveying CSFV-antibody titers in pigs.
Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China. lixuewu2002@126.com
Xuewu
X
Li
Li
L
Wang
Xibao
X
Shi
Dong
D
Zhao
Jifei
J
Yang
Suzhen
S
Yang
Gaiping
G
Zhang
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D002846:Chromatography, Affinity / Q000379:methods*; D006691:Classical Swine Fever / Q000175:diagnosis* / Q000276:immunology; D006692:Classical Swine Fever Virus / Q000235:genetics / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D017979:Gold Colloid; D011934:Reagent Strips; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology*; D012680:Sensitivity and Specificity; D013552:Swine; D013553:Swine Diseases / Q000175:diagnosis / Q000276:immunology / Q000821:virology; D013997:Time Factors; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology*
D000914:Antibodies, Viral; D017979:Gold Colloid; D011934:Reagent Strips; D011994:Recombinant Proteins; D014759:Viral Envelope Proteins