After ethanol precipitation, the resuspended siRNA mixture is ready for transfection in mammalian cells using reagents and protocols suitable for oligonucleotide transfections. Alternatively, calcium phosphate or electroporation may be used; both have been reported to be efficient in transfecting short RNAs (4).
A very small amount of siRNA is sufficient for effective silencing as compared to single sequence siRNAs (1). We recommend testing 25–100 ng of siRNA per transfection well (24 well format) as a starting point. In this format, these amounts correspond to approximately 5–15 nM.