HIV-1 provirus expression after LRA treatment. (A) Frequency of cells expressing HIV-1 LTR, gag, and env transcripts after treatment with LRAs estimated by poison distribution, based on limiting dilution data and calculated using the MPN method. (B) Average copies of transcripts per expressing cell. The number of LTR, gag, and env transcripts per reaction was determined based on a standard curve. Average copies of transcripts per expressing cell were estimated based on the frequency of cells expressing HIV-1 transcripts as shown in A. LRAs had no effect in HIV-1 provirus activation (data not shown) for clone 603. All experiments were performed in triplicates.