0.2. μM of bafilomycin A1 or various concentrations of diphyllin (0.078, 0.312, 1.25 μM) were added to MDCK cells one hour before NS1-GFP virus infection (MOI = 0.01). Infected cells without diphyllin treatment were used as controls. After a 1-hour period of infection, cells were washed, overlaid with fresh media containing the same concentrations of diphyllin as in previous step, and incubated for another 24 hours. (A) Fluorescence images of GFP (green) and nucleus (DAPI, blue) were acquired using DeltaVision deconvolution microscope system. Representative images are shown (magnification: 200×). (B) Green fluorescence intensity from diphyllin-treated cells was quantitated using an iCys Research Imaging Cytometer. Data was presented by the relative intensity of untreated controls cells. Values are mean ± SD from four replicates.