Inhibition of HIV-1 replication in MDMs by flavopiridol. MDMs were isolated from healthy donors and infected with HIV-1p256 along with increasing concentrations of flavopiridol. Supernatants were collected at 4, 8, 12 and 16 days post infection. The amount of HIV-1 infection was measured by quantifying the amount of HIV reverse transcriptase enzyme (RT) in the supernatants on the indicated days (BOTTOM graph). Cytotoxicity studies were performed on uninfected MDMs by treating cells with different concentrations of flavopiridol for 4, 8, 12 and 16 days and measuring cell viability by the ATPLite assay. The light readings were normalized to the mock treated cells and plotted (TOP graph). The experiment was performed in MDMs twice and the data from both experiments was pooled, averaged and graphed.