Effect of DMSO in the productive infection of HSV-1. Cultured Vero cells (105 cells in 24-well plates) were infected with 1 million PFU of the dUTPase/LAT recombinant virus. After 1 hr adsorption period, overlay medium was added containing the indicated concentrations of DMSO. At 24 hr post-infection, the cells were harvested and the virus yield was determined by plaque assay. Data are the average ± SD of 3 duplicate determinations.