HbF is present only in the transduced fraction of cultured erythroblasts. (A) Fluorescence-activated cell sorting of GFP− and GFP+ fraction of erythroblasts derived from adult-mobilized PB CD34+ cells transduced with SpGG1-VP64 vector where the morphology of sorted cell populations is presented as Wright-stained cytocentrifuge preparations (original magnification ×60) imbedded within histograms for GFP− and GFP+ cell populations, respectively. (B) Hb electrophoresis of lysates from various cell populations (vertical lines have been inserted to indicate a repositioned gel lane). (C) HPLC analysis of lysates from the GFP− and GFP+ cell populations.