Selective Modification of Chitosan to Enable the Formation of Chitosan-DNA Condensates by Electron Donator Stabilization

Figure 4

Plasmid DNA at a concentration of 10 μg/mL was vigorously mixed with an equal volume of modified chitosans in a pH 7.4 buffer to yield various stoichiometric charge ratio of modified chitosans to DNA. In the control, DNA was mixed with buffer, no chitosan present in the reaction system. Upon mixing, the reaction tubes were incubated at room temperature for 60 mins and centrifuged for 90 mins at 4°C. Addition chitosan-DNA complexes were separated by centrifugation. The supernatants were carefully pipetted off, and the pellet in each case was resuspended in intracellular saline. ABS 260 nm was measured for both the supernatants and pellets. Data was averaged over six independent experiments, with triplicates for each data point within each experiment. A standard error of less than 5% was obtained for data points reported.