Development of a colloidal gold immunochromatographic test strip for detection of lymphocystis disease virus in fish

Aims To develop a gold immunochromatographic test strip for on‐site rapid detection of lymphocystis disease virus (LCDV). Methods and Results Monodispersional colloidal gold and gold‐labelled anti‐LCDV monoclonal antibody (McAb) 2D11 were prepared and characterized by UV‐visible spectroscopy and transmission electron microscopy. Gold‐labelled probe was used as the detection antibody, and goat anti‐mouse IgG at the control line and anti‐LCDV McAb 1A8 at the test line of the test strip served as the capture antibody. The positive results could be easily judged by the presence of a red test line with naked eye within 10 min. The test strip, in good agreement with enzyme‐linked immunosorbent assay and dot‐blotting in sensitivity and LCDV detection, gave a detection limit of 1 μg ml−1 of LCDV and was stable for 6 months at room temperature and 12 months at 4°C. Conclusions The test strip was specific, simple and convenient for rapid detection of LCDV presenting good stability and reproducibility. Significance and Impact of the Study This ready‐to‐use test strip allows on‐site rapid detection of LCDV in fish without the requirement of specialized equipments and professional personnel, which could augment the practical application for diagnosis of LCDV even in disadvantage areas.