Sigma-Aldrich launches new RNAi screening tool

Unlike traditional synthetic RNAi, esiRNA incorporates a pool of hundreds of siRNAs against a single gene target. This new tool is designed to eliminate the trial and error approach of identifying a single siRNA for gene knockdown and ensures minimal off-target effects, said Sigma-Aldrich.

According to the company, the technique offers a number of benefits over the traditional approach to single-siRNA gene knockdown. By targeting each gene target with a ‘super-poo’ of siRNA, the trial and error approach of identifying a useful single siRNA is eliminated. In addition, the approach should ensure minimal risk of off-target effects and enables the use of one assay per gene.

Development of the esiRNA approach was supported by the German BMBF program ‘GO-Bio’ and developed by the Max Planck Institute for Cell Biology and Genetics in Dresden, Germany. Harvard Medical School, which has invested in a human genome-wide esiRNA library, is using esiRNA to help identify the human genes that enable HIV propagation. Harvard Medical School will soon incorporate the technology into a wider range of tests.

esiRNA are endoribonuclease-prepared siRNAs synthesized by in vitro transcription of a 300-600-bp gene specific double-stranded RNA, followed by enzymatic digestion. This collection of siRNA-like molecules is then purified, resulting in a complex pool of siRNA molecules all targeting different sequences of a single gene.

Supriya Shivakumar, global marketing manager for functional genomics at Sigma-Aldrich, said: “MISSION esiRNA provides a powerful way to elucidate gene function in cell culture assays. The pooled format, unlike anything else on the market, should enable researchers to knock down genes rapidly and cost-effectively. This is an exciting addition to our current MISSION lineup and provides an effective technology that will facilitate RNAi research for a broad base of scientists.”