Figure 2From: Targeted gene delivery in tumor xenografts by the combination of ultrasound-targeted microbubble destruction and polyethylenimine to inhibit survivin gene expression and induce apoptosisElectrophoretic patterns of plasmid DNA complexes prepared with PEI at various N/P ratios: N/P ratio = PEI nitrogen/DNA phosphate; (A) pCMV-LUC, (B) pSIREN-S. Lanes 1-10: the N/P molar ratios of 1/4, 1/2, 1, 3/2, 2, 5/2, 3, 4, 6, and 8.Back to article page