Development of dot-immunogold filtration assay to detect white spot syndrome virus of shrimp

The dot-immunogold filtration assay (DIGFA) detects white spot syndrome virus (WSSV) by using a nitrocellulose membrane (NCM) as a support of WSSV and anti-WSSV monoclonal antibodies (MAbs) 1D5 and 6A4 labelled with red color colloidal gold. The principle of filtration for the rapid reaction of antigen and antibody is adopted in order for the test process to be completed within 3 min without incubation or any equipment. A reddish dot indicative of a positive result is present visibly. In comparison with dot-blot nitrocellulose enzyme immunoassay (DB-NC-EIA), the sensitivity of DIGFA is similar. However, DIGFA is a method that can be performed conveniently pond side providing a faster result without the production of false positive results.