In vitro REP 9 Activity against MCMV infection at Different Times during Infection. Plaque reduction assays were performed with no REP 9 compound added or 10 μM REP 9 present throughout the assay, or present for 0-2 hours of the assay, or present only after 2 hours or 10 hours after infection and the remainder of the assay. Addition of 10 μM Ganciclovir in the assay served as a control for inhibition of MCMV replication. Mean antiviral activity is depicted as percentage of plaques in REP 9 wells relative to the percentage of plaques in control wells. Data is from two separate studies and assays performed in triplicate wells.