Development of a lateral flow immuno‐chromatic strip assay for the detection of cyprinid herpesvirus 3 (CyHV‐3)

Abstract

Cyprinid herpesvirus 3 (CyHV‐3) is the main pathogen of koi herpesvirus disease (KHVD), which has caused serious damage to the ornamental and food‐producing carp industry. Effective and rapid on‐site detection methods are needed for early diagnosis of CyHV‐3. A lateral flow immuno‐chromatographic assay (LFIA) using two specific anti‐CyHV‐3 monoclonal antibodies has been developed and validated for on‐site detection of CyHV‐3. MAb 3C9 was used to bio‐conjugate CyHV‐3 antigen with colloidal gold, and MAb 2A8 was used to capture antigen bound colloidal gold on the test line. The control line was lined with goat anti‐mouse IgG to capture unbound colloidal gold to validate performance. The test results can be viewed within 10 min after putting the strip into CyHV‐3 virus infection fluid. The lowest limit of detection for the LFIA test was found to be 1.5 × 104 copies/μL and it showed no cross‐reactivity with other fish viral pathogens. The specificity of the strip was 100% when spleen and kidney tissues of CyHV‐3‐infected and healthy koi were validated at the field level. The LFIA strip will be an effective device for the early detection of CyHV‐3 in the future.