A simple and efficient method for purification of intact white spot syndrome virus (WSSV) viral particles

A new simple and efficient method for isolation of intact WSSV viral particles from infected crayfish tissues with high yield was developed. Abundant viral particles could be obtained with only a few steps of conventional differential centrifugations, while no density gradient centrifugation or ultracentrifugation was required. The concentrated virus preparations were further studied by transmission electron microscopy and polyacrylamide gel electrophoresis. Using negative-staining TEM, we found that purified viral particles were coated with integral envelope. At least 23 major structural proteins from purified WSSV virions could be observed by SDS-PAGE. By this method, about 10(12) viral particles could be recovered from 10 g of infected crayfish tissues. Moreover, purified virus does not lose its biological activity. Using purified virus, the minimal amount of WSSV that could initiate a successful virus proliferation in crayfish was determined.