Figure 1.

Detection of BrdUrd-labeled CD4⁺ cells. EDTA anticoagulated whole blood samples were drawn from an uninfected individual (A) and two patients infected with HIV-1, one with low viral load and high CD4⁺ count (B) and one with high viral load, low CD4 count (C), and assayed for ex vivo BrdUrd incorporation into CD4⁺ T cells. (A–C) Whole blood was incubated with (Right) and without (Left) BrdUrd for 4 h at 37°C. (D) BrdUrd incorporation into CD4⁺ T cells of an individual with HIV-1 infection was determined before (Left) and 1 day after (Right) a 30-min infusion of BrdUrd (200 mg/m²). Cell surface staining and flow cytometric analysis of ex vivo- and in vivo-labeled cells were performed by using the same procedure.