FIG 2.

Anti-HIV-1 activity of ribonucleoside analogs. Permissive target cells were pretreated with increasing concentrations of each ribonucleoside analog under investigation and then infected with equivalent amounts of the HIV-1 vector. At 48 h postinfection, cells were analyzed by flow cytometry to determine the percentage of infected cells, displayed relative to the amount of the vehicle control on a log-linear plot. Cell viability was determined by measuring the abundance of ATP after a 24-h exposure to each ribonucleoside analog. The EC₅₀s and the TC₅₀s were determined using a nonlinear regression equation for best fit.