“…The titer of baculoviral stock is an essential parameter during transduction because the transduction dosage in MOI is obtained from the titer, and therefore it is necessary to measure the titer of any batch of viral stock. In previous studies, various methods have been applied to quantitate recombinant baculoviruses, such as the traditional plaque assay [18], flow cytometry assay [19], immunological assay [20], MTT assay [21], alamar blue assay [21], quantitative real-time PCR [21,22], methods based on visible cell sizes [21,23], viable cell side scatter [24], etc., most of which take up to several days, require expensive detection kits, or entail multiple laborious operation steps. In this study, the titer of baculoviral stock was quantitated based on an end-point dilution method with fluorescence, which is sensitive and rapid because of the robust promotor and luminous fluorescent signals, economical due to the simple reagent, and convenient to operate, as previous studies have demonstrated [21,25,26].…”