Separation of CD34⁺CD41⁺ human BM cells. Correlated two-parameter histogram of staining of (A) low-density BM cells after enrichment of the CD34⁺ population using magnetic beads (MACS) and two cycles of sorting. The separated population is 99% CD34⁺ and 98% CD41⁺. (B) DNA content of isolated CD34⁺CD41⁺ BM cells. In this sample, 15% of the cells are in S phase and 17% are in G2-M or have reached the 4N stage via endomitosis. Less than 0.5% of the cells in this sample have a DNA content ≥8N. The data were collected in log mode. (C) Morphology of purified CD34⁺CD41⁺ BM cells. The CD34⁺CD41⁺ cells shown in (A) were deposited on slides by cytocentrifugation and stained with Wright-Giemsa. (Original magnification × 630.)