Demonstration of Venezuelan Equine Encephalomyelitis in Tissue Culture By Immunofluorescence

Abstract

An egg-adapted strain of Venezuelan equine encephalomyelitis (VEE), Trinidad, adapted to a guinea pig heart cell line was used as a model to investigate the use of immunofluorescence in the detection of virus in tissue culture cell lines prior to cytopathogenic changes (CPE) in infected cells. Whole serum prepared in a burro, conjugated with fluorescein isothiocyanate with Lissamine rhodamine conjugated albumin added as a counterstain, proved the best reagent. When heavily inoculated, specific immunofluorescence could be detected as early as 10 hours, and in 24 to 48 hours with an inoculum not showing cytopathogenic changes during the period. The antigen was stable in formalin at 4[degree] C up to 2 weeks, while with other fixatives the stability of the antigen diminished rapidly. This model indicates the possibility of obtaining a specific viral diagnosis at the clinical level in the period normally required for initial isolation by conventional cell culture technics.