RNAiRNA interference (RNAi) is characterized by targeted mRNA degradation after introduction of sequence-specific double
stranded RNA (dsRNA) into cells. Although cellular uptake of long dsRNA by organisms such as C. elegans and Drosophila has proven to be an effective method to induce RNAi, it tends to result in non-specific gene suppression in
vetebrate cells due in part to interferon response. Following earlier discoveries, it is well established today that short dsRNAs, or small interfering RNAs (siRNA) of less than 30 nucleotides, cause gene-specific silencing in mammalian cells. In addition, the RNAi effect caused by siRNA can be detectable even after many cell divisions.
RNA interference (RNAi) has become a very important tool for studying gene functions because it allows sequence specific gene suppression in a variety of organisms and cultured cells. RNAi is characterized by targeted mRNA degradation after introduction of sequence-specific double stranded RNAs (dsRNAs) into cells. Several studies indicate that RNAi is an evolutionarily conserved defense mechanism directed against invading viral genomes or aberrant transcription products. In vitro studies using Drosophila lysates revealed that 21-25 nucleotide small interfering RNA duplexes (siRNAs) are the mediators of gene silencing. These siRNAs are derived from processing of the dsRNA by an RNase III-like enzyme. The mechanism involves the recruitment of siRNAs into a multi-protein complex known as RNA Induced Silencing Complex (RISC), which interacts with the target RNA to mediate cleavage in a catalytic fashion.
Complex pools of siRNAs can be produced by incubating in vitro transcribed long double stranded RNAs (~500bp) with recombinant RNase III or recombinant human Dicer enzyme. These pools compare favorably with chemically synthesized siRNAs in terms of their effectiveness and off-target effects and they have been successfully applied to both large scale screens and functional studies of individual proteins.
Genlantis offers a series of RNAi products for achieving targeted gene suppression. These include the highly optimized GeneSilencer siRNA Transfection Reagent for efficient and functional siRNA delivery as well as the Dicer and Turbo Dicer siRNA Generation kits and components for enzyme-mediated in vitro production of heterogeneous siRNA cocktails.