In vivo binding of SB transposase. Untreated or CpG-methylated p5SB-luc reporter plasmids were co-transfected with/without the activator plasmid pc-SB(123)-AD and with/without a full-length SB transposase competitor into HeLa cells. After 48 h luciferase expression was determined. To compare the effect of CpG methylation, ratios were calculated by dividing the value for luciferase expression with untreated donor plasmids by the value for luciferase expression with CpG-methylated donors. Three independent experiments are shown. No statistically significant differences were obtained.