Lentiviral vector-mediated transduction of erythroid progenitors derived from cytokine-mobilized PB CD34⁺ cells. (A) Schematic representation of the lentiviral vector encoding for expression of GFP from a modified MSCV LTR sequence. (B) Expansion of cultured cells after transduction. (C) GFP expression is indicated as a function of time after transduction of cells exposed to vector particles at an MOI of 10. (D) Phenotypic comparison of cells on the day of transduction (left panels) and 14 days later at the time of termination of the cultures (right panels) by flow cytometry for expression of the CD34, CD45, CD71, and CD235 surface markers where percentages indicate the proportion of cells considered positive, cell volume, and cell morphology (Wright-Giemsa staining, original magnification × 60). (E) The results of cellulose acetate Hb electrophoresis of lysates from terminal-stage erythroblasts from 2 separate experiments (vertical lines have been inserted to indicate a repositioned gel lane) and (F) HPLC analysis of Hbs present in erythroblasts at the end of culture, which were derived from cells exposed to vector particles at an MOI of 10. The percentages indicate the proportion of Hb species.