Analysis of human BOECs transduced with lentiviral and γ-retroviral vectors. Human BOECs were transduced with Lenti-CMV-GFP or Retro-CMV-GFP at an MOI of 6 and 60 and analyzed by fluorescent microscopy (A) and flow cytometry (B). Percentage of GFP⁺ cells within the M1 marker interval was indicated. Background fluorescence in negative controls corresponded to less than 0.5% positive cells. (C) A quantitative assessment of vector genome copies was determined by quantitative real-time PCR with primers specific for the WPRE element which is common between the 2 different vector types. Primers specific for the endogenous gene GAPDH were used as control for normalization. Data are mean ± SEM; n = 3.