Expression data of the d2 × 250 bp vectors. (A-D) Flow cytometric data for the transduction of naïve RN33B cells with d2 × 250 bp vectors and controls at MOI 1 and 5 (functional titer). Cells were analysed 7 days after transduction. The percentage of GFP-positive cells is shown (A and C) along with the mean fluorescence (MFU) (B and D). Error bars denote standard deviations. E-F: Dose-response curves showing CMV.SIN, d2 × 250 bp.CMV and 1.2 kb.CMV vector performance in naïve RN33B cells. The percentage of GFP positive cells (E) and mean fluorescence is shown (F).