Plaque assay and TCID50 assay are helpful methods for determining viral titers. TCID50 assays are being used to determine the infectious titer of any such virus types, which can cause cytopathic effects (CPE, structural changes in a host cell resulting from viral infection) in tissue culture over a reasonable period of 5 to 20 days while cells in culture remain viable. https://antiviral.creative-dia....gnostics.com/TCID50-