Comparability of bovine virus titers obtained by TCID50/ml and FAID50/ml

In this study, the correlation or comparability was assessed in the values of virus titers measured by either infectivity assay [reported as 50% tissue culture infectious doses (TCID(50)/ml)] or by immunofluorescence assay [reported as 50% fluorescent antibody infectious dose (FAID(50)/ml)]. The results demonstrate that bovine virus titers measured in infected bovine turbinate cells by these two methods are comparable. Clear demonstration of the comparability of these two methods provides a choice of a method for measuring the titer of bovine viruses.