Growth rates of parental and mutant cells and extent of HIV integration. (A) Growth rates. Parental and mutant 30-2 and 42-7 cells were seeded and growth measured over time with the MTT assay. (B) HIV-1 integration. The extent of integrated HIV-1 vector was measured by infection of cells at moi = 1. The cells were passaged 3 times and the quantity of stable HIV-1 DNA was measured by quantitative real time PCR.