System avoids the need to use either costly RNA synthesis or vector systems with user-intensive cloning steps for expression of siRNA directly in mammalian cells
Identification of optimal siRNA-target sequences and testing for suppression of a wide range of genes directly in mammalian cells is now easier using Promega's new Silentgene U6 cassette RNA interference (RNAi) system.
RNAi is a recently discovered phenomenon that is opening up the field of gene function by enabling the targeting and suppression of individual genes.
Such studies can help in mapping cellular pathways, selecting suitable pharmaceutical targets and developing gene therapies.
One of the limitations of RNAi is the need to identify the sequence that will give optimal suppression of the target RNA.
This requires multiple screens to be performed, which can be time consuming and expensive.
By avoiding the need to use either costly RNA synthesis or vector systems with user-intensive cloning steps, the Silentgene system enables rapid evaluation of multiple targets.
Observed suppression using the Silentgene system is equivalent to U6 vector-based systems.
To use the system, the researcher needs to provide the sense and anti-sense DNA primers corresponding to their target(s).
U6 cassette DNA included in the system is used as the template for the primers to produce specific DNA cassettes rather than unstable RNA.
Use of the U6-based system enables the researcher to create different expression cassettes in just a few hours.
There is no need to generate transfection-grade plasmid or perform insert screening: the PCR products are simply purified and then introduced into a suitable cell line using the supplied transfection reagent.
Once introduced into the cells, endogenous U6 polymerase transcribes a short RNA from each of the sense and anti-sense PCR products. These then anneal to form a dsRNA which is incorporated into an RNA induced silencing complex (Risc), directing targeted degradation of mRNA.
Silentgene U6 cassette RNA interference system is designed to study RNAi directly in mammalian cells. Promega produces another system - the T7 Ribomax Express RNAi system - which produces longer dsRNA suitable for transfecting non-mammalian cells.
