Flow cytometric histograms of bcl-2 and bax expressions on 3 AML samples.

AML cases were analyzed by flow cytometry after exposure to anti-CD33 PE and anti–bcl-2 FITC or bax MoAbs, as described. (A) Bivariate histogram FSC/SSC with “blast gate” on leukemic cells and IgG1 isotype-negative controls for bcl-2 (B) or bax (C) and CD33 MoAbs from “blast gate.” Bcl-2 (Di, Ei, Fi) and bax (Gi, Hi, Ii) were evaluated on the CD33⁺ cells segregated by “AML cells” gate in 3 AML cases. Bcl-2 (Dii, Eii, Fii) or bax (Gii, Hii, Iii) univariate histograms, conditioned on “AML cells” gate, show the distribution of fluorescence, reported as arithmetic means (M).