Inactivation of HSV-1 virion infectivity by DMSO. The dUTPase/LAT recombinant virus was suspended in PBS-glucose medium at 2000 PFU/ml and incubated at 37°C for 7 hr. Aliquots of 0.5 ml of the suspension were then adsorbed to Vero cells (105 cells in 24-well plates) for 1 hr. The virus suspension was then replaced with overlay medium, and reporter gene activity was determined at 24 hr. Data are the averages ± S.D of 4 duplicate determinations.