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rnai service quotationRNAi Technology


RNA interference, or RNAi, is a process that sequence-specifically destroys mRNA, causing null or hypomorphic phenotypes. RNAi provides an excellent technology platform for gene expression and gene function studies in many different models, including Drosophila, C. elegans, and mammalian cell systems. RNAi allows researchers to fully or partially suppress the expression of a specific gene, allowing targeted gene knockout and gene knockdown.

Small interfering RNAs, or siRNAs, are short RNA molecules of 19 to 22 nucleotides in length. The siRNAs are generated via cleavage of dsRNA templates by DICER, an RNAse III ribonuclease. The siRNAs are then incorporated into an RNA-induced silencing complex (RISC) and unwound into single-stranded siRNAs. Next, the single-stranded siRNAs guide the RISC complex to the target mRNAs for destruction, causing RNA interference. Depending on the amount of siRNA expressed and its inhibitory efficiency, expression of the target gene can be either completely blocked or measurably suppressed. This allows researchers to determine and study the function of genes, particularly the genes that are lethal upon complete knockout. GenScript's Tet-on and other inducible siRNA expression vectors provide the fine degree of controlled RNAi necessary to these delicate experiments.

  • About siRNA
  • siRNA In vivo
  • About miRNA
  • Selected Publications
 

GenScript vector-based siRNA technology is an adaptation of GenScript gene synthesis technology to the rise of RNA interference (RNAi) as a powerful tool for gene function analysis and drug target validation. The GenScript siRNA technology package includes siRNA design, siRNA vectors, and custom siRNA construction. GenScript siRNA technology has several advantages over synthetic siRNA methods as follows:

  • It produces highly reliable siRNA constructs at minimal cost.
  • Its products are more stable and last longer.
  • It frees scientists from the time-consuming and difficult task of siRNA vector construction.

Vector-based siRNA Technology:

Short siRNA molecules can be prepared either by traditional RNAi methods, which involve the use of synthetic RNA duplexes consisting of two unmodified 21-oligonucleotide molecules annealed together, or by transcription driven by RNA polymerase promoters. The two most critical factors in determining the effectiveness of RNAi experiments are the ability of the siRNA sequence to silence the specific target mRNA and the efficiency with which the siRNA construct or expression vector can be transfected into the cells.

The direct transfection of chemically synthesized siRNA duplexes into cells, originally demonstrated by Rockefeller University's Tuschl Lab, is currently the most popular approach. However, the success of this technique is heavily dependent on the ability of the model cell system to undergo transfection and to sustain the RNAi effect. Also, the noncontinuous presence of siRNA in the cell renders this technique less feasible for long-term studies. This issue, like many other drawbacks of direct siRNA transfection, is completely sidestepped in the case of DNA-vector-based siRNA.

DNA-vector-based siRNA technology, in contrast, involves cloning a small DNA insert of about 70 bp into a commercially available or custom vector. This vector can be transfected into the cell, where the DNA insert expresses a short hairpin RNA. The hairpin RNA is rapidly processed by the cellular machinery into double-stranded siRNA. The use of plasmids allows researchers to use highly reliable GenScript inducible promoters.