Virus growth curve analysis

Infections were conducted in 25-cm² culture flasks containing confluent monolayers of HINAE cells at an MOI of 0.1 PFU per cell. At the end of a 30 min absorption period at 20°C, the inoculum was removed, and the cells were washed three times with MEM containing no serum. MEM (5 ml) containing 5% fetal bovine serum was then added to each culture flask and the flasks were incubated at 20°C. Samples, consisting of 200 μl of medium, were taken at 0, 24, 72, and 120 h post-infection and stored at –80°C. Viral titer was determined for all samples, in duplicate, by a plaque assay using EPC cells. Growth curves were constructed using the mean log titer for each time point.