Agarose gel electrophoresis experiments showing time courses for the release of DNA from polyplexes formed using LPEI and polymer 1e at 0, 24, or 48 hours. All polyplexes were formed at DNA/polymer ratios (w/w) of 1:1, as used in transfection experiments and described in the text. The leftmost lane (lane 0) corresponds to a plasmid DNA control (no polymer added). Lanes labeled 1-4 in each column correspond to polyplexes incubated in the presence of increasing amounts of PAA. DNA/polymer/PAA ratios (w/w) for each lane are 1:1:0 (for lanes marked 1), 1:1:0.5 (for lanes marked 2), 1:1:0.75 (for lanes marked 3), and 1:1:1 (for lanes marked 4). The DNA control in lane 0 (shown for experiments using LPEI) also serves as the internal DNA control for experiments using polymer 1e. These experiments were conducted using the same gel but have been separated in the figure to enhance clarity.