Development of a Monoclonal Antibody-Based Colloidal Gold Immunochromatographic Strip for Detection of Feline Coronavirus Infections

This study aimed to generate a monoclonal antibody (mAb) against feline coronavirus (FCoV) spike (S) protein and to develop a colloidal gold immunochromatographic strip for the rapid and accurate FCoV detection. BALB/c mice were immunized with the purified protein, and hybridoma technology was employed to produce highly effective mAb. A positive hybridoma cell line (E5) was identified, which stably secreted mAb with a high titer of 1:256000 against the FCoV S recombinant protein. Western blot analysis confirmed the mAb E5’s specificity. The established test strip can detect FCoV specifically and detect the antigen concentrations as low as 1.2 × 10 −7 mg/mL. The diagnostic sensitivity and specificity of the FCoV detection strip for feline coronavirus infections were 94.2% and 100%, respectively, as confirmed by reverse transcription polymerase chain reaction (RT-PCR). The detection strip demonstrated no cross-reactivity with other feline pathogens and showed consistent results in reproducibility tests. The developed colloidal gold test strip offers a highly sensitive and specific tool for rapid FCoV detection, contributing to improved real-time epidemic monitoring.