Silencing of gene expression in cultured cells using small interfering RNAs

The discovery of RNA interference (RNAi) and related small RNA-mediated regulatory pathways has significantly altered the understanding of gene regulation in eukaryotic cells. In the RNAi pathway, small interfering RNAs (siRNAs) approximately 21 to 23 nucleotides in length serve as the regulatory molecules that guide and induce sequence-specific gene silencing. The use of siRNA-mediated silencing as a tool for investigating gene function is well established in cultured mammalian cells. This unit provides basic approaches to explore the field of RNAi, and hopes to address the importance of optimizing transfection conditions after empirical determinations in order to understand various degrees of silencing efficiency.