Development of an E2 Protein Based Lateral Flow Assay as a Point-of-Care Test for the Diagnosis of Classical Swine...

Classical swine fever (CSF), a highly contagious viral disease, poses significant threats to pig farming in India and around the globe. In this study, we aimed to develop a rapid and reliable lateral flow assay as a point-of-care (POC) test for CSF diagnosis based on the recombinant CSFV E2 protein. The study began with the confirmation of the recombinant clone, followed by the expression of the CSFV E2 gene in Sf21 insect cells. Characterization of the expressed protein confirmed its presence and reactivity with specific antibodies. Hyperimmune sera raised in rabbits and chickens showed strong reactivity against the recombinant protein. Subsequently, gold nanoparticles were conjugated with the recombinant E2 protein and characterized, demonstrating successful conjugation. The developed lateral flow assay (LFA) exhibited high sensitivity (100%) and specificity (96.42%) when validated against a commercial ELISA kit, making it a reliable tool for on-site CSF detection. Cross-reactivity testing with African swine fever (ASF) sera showed no false positives. The assay also maintained consistent accuracy and functionality during a 30-day shelf-life test at 4 °C. Overall, the developed POC test offers a practical solution for rapid CSF screening, aiding in effective disease management and control in pig populations, particularly in pen-side settings.

The online version contains supplementary material available at 10.1007/s12088-025-01471-2.