DNA analysis performed on CFBE41o- transfected cells harvested 120 hrs after transfection. (A) PCR analysis of wild-type (WT) and ΔF508 alleles as a function of lipid to DNA charge ratios in CFBE41o- cells. Replacement was indicated by the presence of the WT-allele for lipid/DNA ratios ranging from 42+/1- to 1+/1- corresponding to lanes from 1 to 7. DNA from untrasfected cells was amplified in lane 8 as negative control; (B) Densitometric analysis revealed that the maximum correction efficiency is reached with a ratio of lipid/DNA 6+/1-. No correction was observed at 1+/1- ratio.