Figure 2

siRNA-mediated gene silencing in human cells. (A and B) 293 and (C and D) HeLa cells transfected with pEGFP-N3 and antisense (as) ssRNAs and dsRNAs were harvested 48 h after transfection and were assayed for GFP expression by FACS analysis (assayed in triplicate; data are shown as mean ± SEM). A and C show the percentage of GFP-positive cells and B and D show the fluorescence intensity (Geo Mean) of GFP-positive cells. (E–H) HeLa cells transfected with pcDNA3-CAT, ssRNAs, and dsRNAs were harvested 48 h after transfection and assayed for CAT expression (assayed in triplicate and normalized to the amount of CAT pg/μg of protein observed in plasmid plus sense-transfected cells. s, sense ssRNA; as, antisense ssRNA). *, P < 0.05; **, P < 0.01; ***, P < 0.001.