Phenotype of cord blood, bone marrow, and AML cells. Flow cytometry was used to assess the phenotype of cord blood, bone marrow, and AML cells. (A) Percentage of (Lin^-) CD34⁺CD38^- cells expressing CD13, CD33, and CD123 in bone marrow (n = 6), cord blood (n = 12), and AML (n = 18). The error bars represent SD. In panels B-D, the expression profile of CD34 and CD38 is shown in the left plot. (Lin^-) CD34⁺CD38^- cells are denoted by the R1 gate for further analysis. The expression of CD33 and CD13/CD123 on cells in the R1 gate is shown in the middle and right plots, respectively. Cells stained with isotype control are represented by the open histogram in the middle plot. More than 98% of cells stained with isotype control fall within the bottom left quadrant in the right plot. (B) Expression profile of CD33, CD13, and CD123 on Lin^-CD34⁺CD38^- cord blood. (C) Expression profile of CD33, CD13, and CD123 on Lin^-CD34⁺CD38^- bone marrow. (D) Expression profile of CD33, CD13, and CD123 on CD34⁺CD38^- AML cells (sample no. 10). (E) Mean fluorescence intensity of antigens on (Lin^-) CD34⁺ CD38^- cells from bone marrow, cord blood, and AML.