CD33 sorting strategy for AML and engraftment time course of sorted fractions. AML MNCs were stained with anti-CD33 antibody and sorted into CD33^- and CD33⁺ fractions. (A) AML cells stained with isotype control. (B) AML cells stained with anti-CD33 antibody and sort gates G1 and G2. Purity of the sorted CD33^- (C) and CD33⁺ (D) fractions of AML. Engraftment of CD33⁺ and CD33^- fractions of AML samples no. 1 (E) and no. 9 (F) at 6 and 12 weeks. Filled squares represent mice given CD33^- cells. Open squares represent mice given CD33⁺ cells.