Expression of CD33, CD38, HLA-DR, or c-kit on BM- derived CD34⁺ cells (A) or CB-derived CD34⁺ cells (B). Sorting gates were first established for forward scattering and side scattering. Four dual-parameter dotograms displaying FITC (CD34) and PE (CD33, CD38, HLA-DR, or c-kit) fluorescence were then generated from the gated events. (C) Leukemic cells obtained from a patient with AML (M4, patient no. 294) were sorted as described. A dual-parameter dotogram displaying CD34 and CD33 is shown.