Are fluorescently labeled siRNAs good controls?

Historically, many researchers used fluorescein-labeled siRNA and observed a poor correlation of fluorescence with actual siRNA delivery and silencing efficacy. Modifying conventional siRNAs with fluorescent labels may attenuate the functional activity of the siRNA or even completely abolish the siRNA function. In addition, degradation of the siRNA or loss of the fluorescent label can make it difficult to correlate fluorescence with siRNA functionality and lead to over-estimates of siRNA delivery, as the label tends to bind indiscriminately to cells. Dharmacon siGLO Transfection Indicators address these difficulties by localizing signal to the nucleus as an unmistakable sign of delivery success. Additional information about siGLO Transfection Indicators and other siGLO Controls can be found here.