Flow cytometric analysis of erythroid bulk culture cells tracked with PKH26.

Day 6 cultures were labeled with the fluorescent membrane dye PKH26 (see “Materials and methods”). GFP⁺CD13⁻cells from control and AML1-ETO–transduced cultures were analyzed for PKH26 fluorescence at the time points indicated. Histograms (representative from 1 of 3 experiments) show the fluorescence intensity of PKH26-labeled cells (filled histograms) and the fluorescence intensity of equivalent unlabeled cells (open histograms). Placement of the marker region for each culture was adjusted with reference to day 6 of culture (PKH26 labeling day 0).