Dublin, Ireland (PRWEB) March 21, 2013
RNA interference (RNAi) or gene silencing involves the use of double stranded RNA (dsRNA). Once inside the cell, this material is processed into short 21-23 nucleotide RNAs termed siRNAs that are used in a sequence-specific manner to recognize and destroy complementary RNA. The report compares RNAi with other antisense approaches using oligonucleotides, aptamers, ribozymes, peptide nucleic acid and locked nucleic acid.
Various RNAi technologies are described, along with design and methods of manufacture of siRNA reagents. These include chemical synthesis by in vitro transcription and use of plasmid or viral vectors. Other approaches to RNAi include DNA-directed RNAi (ddRNAi) that is used to produce dsRNA inside the cell, which is cleaved into siRNA by the action of Dicer, a specific type of RNAse III. MicroRNAs are derived by processing of short hairpins that can inhibit the mRNAs. Expressed interfering RNA (eiRNA) is used to express dsRNA intracellularly from DNA plasmids.
Delivery of therapeutics to the target tissues is an important consideration. siRNAs can be delivered to cells in culture by electroporation or by transfection using plasmid or viral vectors. In vivo delivery of siRNAs can be carried out by injection into tissues or blood vessels or use of synthetic and viral vectors.
Because of its ability to silence any gene once the sequence is known, RNAi has been adopted as the research tool to discriminate gene function. After the genome of an organism is sequenced, RNAi can be designed to target every gene in the genome and target for specific phenotypes. Several methods of gene expression analysis are available and there is still need for sensitive methods of detection of gene expression as a baseline and measurement after gene silencing. RNAi microarray has
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