Figure 5: Comparison of percentage of EGFP gene silencing by CS/PLA/siRNA complexes at various weight ratios in HeLa cells stably expressing EGFP after 4 days posttransfection at pH 7.4 between in the absence of serum (black bars) and the presence of serum (gray bars). The PEI (25 kDa)/siRNA at weight ratio of 2 : 1 was used as a control. Data are plotted in mean SD ( ).