FIG. 3.

Single-step growth assay of recombinant VSV in BHK-21 cells. Confluent BHK-21 cells were infected with individual viruses at an MOI of 3. After a 1-h adsorption, the inoculum was removed, the cells were washed with DMEM, and fresh medium (containing 2% fetal bovine serum) was added, followed by incubation at 37°C. Samples of supernatant were harvested at the indicated intervals over a 48-h time period, and the virus titer was determined by plaque assay on Vero cells. Titers are reported as the mean ± the standard deviation among three independent single-step growth experiments.