Effect of DMSO treatment on productive infection 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 was present for 24 h before adsorption (filled circles), during the adsorption phase (open circles) or for 23 hr after the adsorption period (filled triangles). Also included is the effect of DMSO present for 23 hr after adsorption on HFF cells infected under similar conditions (open triangles). Reporter gene activity was determined at 24 hr following infection. Data are the average ± SD of 3-6 duplicate determinations.