FIG. 3.

DNA contents and transcription levels are not affected by the WPRE. 293T cells were transduced with HR′CMV-GFP and HR′CMV-GFP-W vectors at an MOI of 0.2. GFP-positive cells were sorted, expanded, and used for comparative DNA and RNA analyses. (A) Southern blot. Genomic DNA extracted from HR′CMV-GFP-transduced cells (lanes 1 and 3) or HR′CMV-GFP-W-transduced cells (lanes 2 and 4) were hybridized with a GFP-specific probe (lanes 1 and 2). The membrane was stripped and rehybridized with a GAPDH-specific probe (lanes 3 and 4). (B) WPRE does not increase transcription initiation frequency. Radiolabeled transcripts produced by nuclear run-on transcription were hybridized to plasmid DNA encoding GAPDH or histone 2B or PCR-derived DNA.