Establishment And Preliminary Application Of Double Antigen Sandwich Method Strip For Detecting Of Pedv Antibody

Porcine epidemic diarrhea virus(PEDV)is the etiologic agent of porcine epidemic diarrhea(PED)and causes acute and highly contagious intestinal disease in pigs.Since it was first identified in the 1970 s,outbreaks have occurred all over the world,causing huge economic losses to pig breeding and seriously threatening the healthy development of pig breeding.In order to better prevent and control PEDV,it is necessary to strengthen the surveillance of PEDV antibody.Currently,there are several methods and commercial kits for the detection of PEDV antibody Ig G,Ig A or Ig M,but there is no test that is not limited by the type of antibody.Lateral flow immunochromatographic assays(LFIAs)and double antigen sandwich method were used in this study.PEDV S1 protein expressed in eukaryotic system(fused with human Fc fragment)was used to label color microspheres and act as T-line coated antigens.By optimizing strip materials,buffer system and detection conditions,PEDV antibody detection strips were detected by double-antigen sandwich method.The results showed that compared with 200 nm red latex microspheres,300 nm red microspheres had more complete release,better tracer effect,and more uniform and vivid color development on T-line and C-line.Sheep anti-human Ig G was selected as C-line coated antigen.The sensitivity of the developed test strip for antibody detection can reach 1:1024 and can be stored at 4℃ for at least half a year.There was no reaction with PRV positive serum,PRRS positive serum,PCV3 positive serum,FMDV positive serum and CSFV positive serum.The same 61 PEDV serum samples were detected simultaneously with a commercial PEDV antibody detection ELISA kit,and the Kappa coefficient of both detection results was 0.80.With a high degree of consistency;In 144 clinical samples with known background,the overall coincidence rate was 91.60%.In conclusion,this study successfully developed PEDV antibody detection strip with double antigen sandwich method,which has good specificity,sensitivity,repeatability and stability,and can be used for field detection.It provides a rapid,accurate and simple field detection method for PEDV antibody detection,and has good application potential and prospect.