Flow cytometric analysis of propidium iodide stained CD34⁺/CD38⁻ cells obtained from MPB. (A) The immunomagnetic separation of CD34⁺/CD38⁻ cells obtained from selected CD34⁺ cells. Greater than 90% of CD34⁺cells were CD38⁺. The MFI for CD38⁺ cells was 675. After negative selection, the MFI for CD38⁻cells reduced to 15. (B) Histogram showing PI-fluorescence of selected CD34⁺/CD38⁻ cells stained with two-color immunofluorescence (CD34-FITC and PI) and gated on CD34⁺cells. M1 defines cells in G0/G1 phase, M2 defines cells in S phase, and M3 defines cells in G2+M phase.