TABLE 2.

RNA interference in mammalian cell lines is differentially induced by siRNAs^a

Cell type	Relative mean fluorescence intensityb		Fold Decrease in EGFP expressionc
	No siRNAs	With siRNAs
BSR T7/5	3,813	1,593	2
BHK21	1,030	224	5
HeLa	1,164	131	9

^aBSR T7/5, BHK21, and HeLa cells were cotransfected with plasmids pEGFP-N1 and pHcRed1-C1, either in the absence (no siRNAs) or the presence (with siRNAs) of EGFP-specific siRNAs, as described in the legend to Fig. 3. Forty-eight hours later, cells were fixed in 4% paraformaldehyde and subjected to flow cytometry as described in the text.

^bThe relative mean fluorescence intensity for EGFP for each cell line, in the absence or presence of siRNAs, was measured in the population of cells expressing both EGFP and HcRed1 fluorescent proteins.

^cRelative effect of siRNAs on EGFP expression.