Time course dependency of DMSO blockade of productive infection. Cultured Vero cells (105 cells in 24-well plates) were infected with 1000 PFU of the dUTPase/LAT recombinant virus. After the adsorption phase, 4% DMSO was added in the ovelay medium and kept for the indicated time periods. At those times, the media were replaced with fresh overlay medium without DMSO and the incubation continued 24 hr. Reporter gene activity was determined at 24 hr post-infection. Data are the average ± SD of 3-6 duplicate determinations.