Rapid Detection Of Classic Swine Fever Virus By Colloidal Gold Conjugated Test Paper

A simple method was developed for the detection of classic swine fever virus in clinical samples using gold immunochromatography(GICA).The classic swine fever virus vaccine was used to immunize rabbits and cocks.The immunized sera were purified by caprylic acid/ammonium sulfamate precipitation reaction.The resultant immunoglobulin G(IgG) was analyzed by the conventional PAGE and agar diffusion assay. The PAGE showed that the purified antibodies consist of Y globulin and a little other globulin.The activation of two kinds of immunized sera and purified IgG in agar diffusion assay were 1:16. Tri-sodium citrate with aqueous gold chloride were warmed up and mixed to synthesize gold sol. The 15nm colloidal gold particles were selected from the primary preparation of colloidal gold nanoparticles which showed different color and judged esaily. The multiclonal antibody against classic swine fever virus was labeled with the selected gold sol. When 1 milliliter of the selected gold sol was labeled, 40μg purfied antibodies were needed at least.The labeled rabbit IgG against classic swine fever virus was purified on low temperature ultra centrifuging. The labeled rabbit IgG against classic swine fever virus was diluted in TBS(containing 1% BSA) at the ratio of 1:2. The chicken anti-CSFV antibody and sheep anti-rabbit antibody were immobilized to different areas of nitrocellulose membrane. The optimized concentrations of two antibodies were 750μg/mL and 500μg/mL respectively ,in terms of titration of the square matrix test.A good recipe was valid and was used to prepare the storing labeled rabbit IgG against classic swine fever virus.Our result showed the potential of detecting and releasing was very promising when the test paper was stored at 4℃ in desiccator for 4 monthes.The clinical samples of classic swine fever were detected by the test paper. At the same time,two different methods including FA and RT-PCR were tested in parallel.The result showed that this method was easy to be justified,time-saving,differential and suitable for field test and epidemiologic investigationIt could be concluded that our new GICA system has paved the way for a rapid diagnosis of classic swine fever clinically.