Effect of 8 hr treatment of DMSO at different phases of infection. Cultured Vero cells (105 cells in 24-well plates) were infected with 1000 PFU of the dUTPase/LAT recombinant virus. Treatments were as follows: DMSO at the indicated concentrations were present for 8 h before adsorption (filled circles), 8 h immediately after adsorption (open circles) and 16 to 24 hr (triangles). Reporter gene activity was determined at 24 pi. Data are the averages ± S.D. of 3-6 duplicate determinations.