2.5. Stability of siRNA/peptide complexes in serum
The stability of siRNA in complexes was confirmed using the agarose gel electrophoresis. 100 pmol of siRNAs and peptides (20:1 N/P ratio) were self-assembled for 30 minutes at room temperature. Then, the complexes in 10% (v/v) FBS were incubated at 37°C, and 20 μL of each sample was collected at 24, 48, 72, and 96 hours. On the other hand, the complex in 50% (v/v) FBS was incubated at 37°C, and 20 μL sample was collected at 4, 8, 12, 24, and 48 hours. The siRNAs were dissociated from complexes using incubation at 37°C for 30 minutes after the addition of 4 μL of 1 mg/mL heparin. After mixing the 6X loading dye to each sample, 24 μL samples were loaded into 2% agarose gel with 1X TAE buffer in Mupid-2plus. Gel running was performed for 30 minutes at 25 VA. The remaining siRNA was analyzed by the gel documentation system LSG 1000 (iNtRON Biotechnology, Seongnam, South Korea).