Researchers performing siRNA screens often employ hundreds or even thousands of siRNAs per experiment
As with experiments using individual siRNAs, effective negative and positive control siRNAs are essential for determining transfection efficiency and to control for the general effects of siRNA delivery in these screens. Negative control siRNAs are also critical for setting the “hit” threshold that determines whether an siRNA is considered as having a positive, negative, or neutral effect in a particular assay. Because of their importance, and due in part to the fact that some negative control siRNAs may have unintended effects in a particular assay, most researchers carefully test their negative control siRNAs before choosing ones for inclusion in their screen.
Figure 1.Effects on Relative Cell Number after Transfections with Silencer® Screening Control siRNAs. UMR106 (A) and HeLa (B) cells were reverse transfected with 30 nM siRNA [Silencer Negative Control siRNAs (A) and Silencer Kif11 siRNA (B)] in triplicate using siPORT™ NeoFX™ Transfection Agent. Three days after transfection, the cells were harvested, and the relative number of cells in each sample was measured in a fluorescence plate reader using a fluorescein diacetate substrate.
As an added benefit, a positive control siRNA to human, mouse, and rat Kif11 (Eg5) is included. Knockdown of Kif11, which encodes a kinesin family motor protein, leads to mitotic arrest (Figure 1B). Effective delivery of Kif11 siRNA can thus be easily assessed visually; it can also be measured by several cell-based assays.
Each of the seven negative control siRNAs, as well as the Kif11 siRNA, in the Silencer siRNA Screening Control Panel is provided dried at 1 nmol. Each control siRNA is also available individually at 5 nmol and can be custom packaged to provide larger amounts.