A sensitive plaque assay for bovine rotavirus in cultures of the bovine cell line GBK.

The Lincoln strain of bovine rotavirus was found to replicate with cytopathic effects in cultures of GBK cells, a stable cell line derived from bovine kidney, when the cultures were maintained in the presence of trypsin. The virus was readily passaged and the infected cells were shown to contain specific viral antigen by indirect immunofluorescent staining. The virus formed plaques in GBK cell monolayers, when trypsin was incorporated in the agar overlay medium. The plaque count increased about twofold when diethylaminoethyl dextran was further included in the overlay medium. Plaque assay in GBK cells was more sensitive than that in MA-104 cells previously reported by Matsuno et al. The specificity of plaques was confirmed by specific inhibition with antiserum against the Lincoln strain.