Rapid titer assay of adenovirus containing green fluorescent protein gene using flow cytometric analysis

Abstract

The plaque assay has been widely used for titration of adenovirus (AdV). However, it takes usually 2-3 weeks, so this slow assay often impedes bioprocess development of large-scale AdV production. In this study, we developed a rapid AdV titration assay that can be done within a day. Further, unlike the plaque assay, this assay does not require a laborious serial dilution of samples. This rapid assay can be achieved by using green fluorescent protein (GFP) as a marker gene and flow cytometric analysis. It yields a good correlation between infectious titer of AdV harboring GFP and flow cytometric parameters such as average green fluorescence intensity or % of infected cells. Taken together, this rapid assay will facilitate bioprocess development for efficient large-scale AdV production.