Figure 2. Cell cycle distribution and cell death in PBL from different age groups. Cultivated PBL were fixed and DNA content analyzed by propidium iodide staining and flow cytometry. Percentage of live cells in G1-, S-, and G2-phase (A) and proportion of dead cells, determined by subG1-DNA content (B); female: n=11 (young), n=8 (old); male: n=2 (young), n=6 (old) (