Cell-cycle analysis of nonadherent and adherent CD34⁺ cells from BM and mobilized PB samples. (A and B) CD34⁺ cells enriched from the BM cells of six donors (A) and from PB cells of four donors (B) were cultured on an MS-5 monolayer. After a 1-hour incubation, nonadherent and adherent cells were obtained for the cell-cycle study. (C and D) BM cells (C) from four donors and mobilized PB cells (D) from four donors were enriched for CD34⁺ cells and cultured with IL-3 and SCF. On day 4 of the culture recovered cells were stained with CD34 MoAb and incubated on an MS-5 monolayer. One hour later, the nonadherent and adherent cells were collected and stained with FITC–anti-CD34 MoAb. CD34⁺ cells were analyzed as to cell-cycle status. The percentages of CD34⁺ cells that were in S + G₂/M phase are presented. ND, not done. *P < .005 by paired t-test.