Development Of Blocking Fluorescent Lateral Flow Immunoassay For On-site Porcine Pseudorabies Virus GE Antibody Detection

Objective: In order to rapidly detect for pseudorabies virus(PRV)g E antibodies and achieve the differential diagnosis of PRV-infected versus vaccinated pigs,a fast and sensitive blocking fluorescence lateral flow immunochromatographic strip(PRV-g EBLFIA)for PRV g E antibodies was established.Methods: PRV virion antigens and goat anti-chicken Ig Y was separately labeled with europium nanoparticles(Eu NPs)to prepare fluorescent probes,and chicken Ig Y as well as PRV-g E monoclonal antibodies was independently coated on the C line and T line.The blocking fluorescence lateral flow immunochromatographic strip(PRV-g E-BLFIA)based on the blocking lateral flow immunoassay strategy was developed for the detection of PRV-g E antibodies.After the strip assembly was completed,a series of process were carried on to optimize the performance.Under optimized conditions,the sensitivity,specificity,repeatability and storage time of the developed strip were evaluated.The clinical samples were tested and compared with IDEXX PRV g E-ELISA kit.Results: The maximum dilution ratio of PRV-g E-BLFIA was 1:80.The cross-reaction rate between PRV-g E-BLFIA and other swine virus infected serum was low,and the coefficient of variation(CV)value of intra and inter batch repeatability was less than 15%.PRV-g E-BLFIA could be stored at room temperature for more than half a year.In tests of clinical samples(n=356),the positive coincidence rate with the IDEXX PRVg E ELISA kit was 91.7%(89/97),the negative coincidence rate was 97.7%(253/259)and the total coincidence rate was 96.1%(342/356).Conclusions: A blocking fluorescence lateral flow immunochromatographic strip has been developed for the detection of PRV g E antibodies.The developed method was sensitive,specific,stable as well as simple,quick and cheap,which was extremely suitable for the on-site differential diagnosis of PRV infection.