Figure 7.
Effect of siRNA dose frequency on the duration of luciferase knockdown by siRNA in nondividing cells. (A) Experimental results using Oligofectamine to deliver siRNA to luciferase-expressing nondividing fibroblasts in vitro. Data points represent the ratio of the average luciferase signal intensity from triplicate wells receiving siGL3 and siCON1. To facilitate comparison of the knockdown kinetics, the data points are normalized such that all three curves exhibit the same magnitude of knockdown for the first four days since all three received the same treatment over this period. This normalization permits comparison of the kinetics of gene silencing observed with different treatments even though the absolute magnitude of the knockdown varied slightly in each experiment. Squares, 100 nM (day 0); diamonds, 100 nM (day 0) + 10 nM (day 4); triangles, 100 nM (day 0) + 100 nM (day 4). (B) Luciferase knockdown after siRNA transfection predicted by the mathematical model using the baseline in vitro parameters given in Table 2 with the number of cells equal to 1.5 × 105, a transfection time of 5 h, and a transfection efficiency of 90%.