FIG. 3.

Induction of RNAi by siRNAs in BHK21 cells. BHK21 cells were cotransfected with plasmids pEGFP-N1 and pHcRed1-C1, either without (A) or with (B) the addition of EGFP-specific siRNAs, as described previously (9). Forty-eight hours after transfection, the cells were fixed in 4% paraformaldehyde and subjected to flow cytometry as described in the text. EGFP and HcRed1 fluorescence were plotted on the x and y axes, respectively, with the cell population that was positive for the expression of both proteins appearing in the upper right quadrant. Representative data are shown; the same pattern was obtained for BSR T7/5 and HeLa cells (data not shown).