Monoclonal antibodies developed for sensitive detection and comparison of white spot syndrome virus isolates in India

Since its first report in 1994, white spot syndrome virus (WSSV) has become widespread in India. We have developed a simple, rapid and sensitive monoclonal antibody (MAb)-based immunodot test for detection of WSSV. Four MAbs of IgG isotype were produced against an Indian isolate of WSSV: 1 MAb recognised a 28 kDa viral protein while the other 3 recognised both 28 and 18 kDa proteins. The 4 MAbs recognised 4 different Indian WSSV isolates collected at different times from the east and west coasts of India, indicating antigenic uniformity of the isolates. The limit of detection of the immunodot test was 500 pg of the viral protein, which compared well with 1 step PCR and could be used to detect WSSV in shrimp Penaeus monodon with and without gross signs of white spots in the cuticle. Furthermore, the test was rapid (3 h for completion) and is suitable for further development as a simple field kit.