RNA Interference (RNAi)
RNAi (RNA interference) is a recently discovered phenomenon that has burst on to the forefront of genetic research. RNAi appears to be an ancient and widespread genetic immune mechanism. Recent breakthroughs have shown that RNAi plays an important role in defending again several types of viruses and is also involved in a number of regulatory mechanisms within the cell. RNA interference is a phenomenon by which the expression of double stranded RNA (dsRNA) specifically stimulates a cellular process that reduces gene expression in a sequence specific manner. Small synthetic RNA, termed small interfering RNAs (siRNA), which are typically 21-28 nucleotides in length, can induce RNAi and knockdown gene expression in mammalian cells without inducing an antiviral response. Biochemical studies have elucidated the mechanism of RNAi. Double stranded RNA is processed by an enzyme known as Dicer resulting in the production of siRNA molecules. These molecules are then able to form a multi-protein siRNA complex, known as the RNA-induced Silencing Complex (RISC). The RISC/siRNA complex catalyzes the cleavage and degradation of the complement mRNA molecules.
At its most basic definition, RNAi destroys molecule messengers that transport information that has been encoded in genes to the protein manufacturing capability of a cell. A number of RNAi capacities are known about and studied, including messenger RNA (mRNA), responsible for transporting genetic information that has a direct impact on the synthesis or creation of specific proteins necessary for cellular replication. A number of viruses are capable of encoding or implanting their own genetic information into cellular structures using the RNA genome (most basically defined as an organism that contains hereditary information) – genomes include genes as well as non-coding sequences of DNA and RNA. Messenger RNA is vital in instructing the cell’s growth and protein synthesis, and without that information or instructions, a gene remains, for all intents and purposes, dormant or inactive. As a double-stranded RNA molecule enters a cellular structure, it triggers RNAi, which is divided into smaller fragments that tell the cell to replicate, matching the specific genetic sequence of those fragments. Then, these smaller segments of messenger RNA are rendered inactive due to their inability to pass along their “messages” or data, which literally shuts down the synthesis of the corresponding gene.
The use of RNAi applications, including small interfering RNA, to reduce cellular gene expression appears to have significant advantages over other approaches for targeted gene regulation. The potency of siRNA molecules, sequence-specific design, and ability of siRNAs to be re-used to guide mRNA degradation in cells bears a significant advantage over anti-sense oligonucleotides and ribozyme-stem approaches. Well-designed and functional siRNAs are capable of effectively bypassing the interferon response in order to induce specific post-transcriptional gene silencing or RNAi in vitro and in vivo.
In Vivo Transfection Kits from Altogen Biosystems
RNAi has been used for in vivo target validation studies using animal models. The major challenge in performing RNAi studies in vivo is the effective, directed delivery of functional small RNA molecules into specific tissues. ALTOGEN® In Vivo Transfection Reagents could be conjugated with siRNA (or microRNA) and administered intratumorally (i.t) or systemically via intravenous (i.v) tail vein injection in order to provide directed gene silencing in specific tissues, including liver, pancreas, kidney, and tumors. Selective knockdown could be seen as early as 24 hours after injection.
Transfection Services by Altogen Labs:
Altogen Labs CRO offers RNAi laboratory services, as well as many other biotechnology and pharmaceutical contract research services, including: in vivo toxicology, xenograft services, development of stable cell lines, RNA interference (RNAi) services, pharmacology and toxicology testing: IC-50, ELISA assay development, siRNA library screening and transfection services, cell banking and cryopreservation services.
Featured in vivo transfection products from Altogen Biosystems:
Altogen Biosystems is a life sciences company dedicated to the development, marketing and manufacture of cell type specific transfection reagents. Efficient delivery of DNA, RNA, and siRNA enabled by advanced formulation of reagents and peculiar design of protocols. Altogen Biosystems offers a complete transfection system for a broad range of cell lines. All reagents are functionally tested to be highly reproducible, serum compatible, induce low toxicity, and can be used for co-transfection experiments, and high throughput applications.