DharmaFECT transfection reagent launched

Dharmacon has launched a range of small interfering RNA (siRNA) transfection reagents designed specifically to enhance transfection efficiency, a crucial procedure in initial drug target identification to late-stage therapeutic development.

Primarily aimed at researchers in drug discovery, functional genomics, and basic cell biology laboratories in pharma, biotech or university research labs, Dharmacon's reagents are ideally suited for drug target validation and are guaranteed to deliver higher levels of siRNA delivery, measured by GAPDH knockdown, by at least 77 per cent when used under appropriate conditions.

With the introduction of Dharmacon's reagents, scientists can now obtain all the reagents needed to conduct transfection experiments, including transfection reagents (along with the conditions suited to a particular cell line), siRNA, controls, and RNA quantitation assays.

Dharmacon has tested its siRNA transfection reagents in more than 20 cell lines, ranging from standard lines (eg HeLa) to those that have been historically difficult to transfect (eg HepG2, THP-1). Optimised for a 96 well plate format, DharmaFECT's panel of lipids can be used to deliver siRNA into a variety of human and mouse cell lines including adherent cells and cells adapted for growth in suspension.

The set consists of DharmaFECT 1, 2, 3 and 4; these siRNA transfection reagents are effective in a wide variety of cell types, according to Dharmacon.

Successful siRNA experiments require a transfection agent optimised for siRNA delivery, the efficiency with which different transfection agents deliver siRNA can vary. Equally important for efficient transfection and reliable results is a transfection protocol that is optimised for the cell type.

The choice of transfection agent is critical for gene silencing experiments using siRNA. Without efficient transfection, siRNA will fail to elicit a cellular response. Most commercially available transfection agents are developed for plasmid transfections and many are limited to a few cell types.

The market for reagents used in siRNA is growing. Recently, Ambion released the Silencer siRNA Transfection Kit contains transfection agents and controls developed specifically for RNA interference (RNAi), or gene silencing.

The kit includes both siPORT Lipid and siPORT Amine transfection agents. They each have different properties to support siRNA transfection of a broad range of cell types. siPORT Lipid is a proprietary mixture of lipids that spontaneously complex with siRNA and facilitate its transfer into cells; siPORT Amine is a proprietary blend of polyamines that delivers siRNA with minimal cytotoxicity. The kit also includes siRNA positive and negative controls for use in protocol development.

siRNA has become the method of choice for a wide range of biomedical applications, in particular emerging as the best functional genomics screening method to identify and validate new drug targets. In so doing, RNAi is not only replacing antisense and ribozyme-based paradigms for cell-based research, but now also offers the promise of a more time and cost-efficient alternative to transgenic mouse knock-out strategies.

In particular, the properties, which make siRNA sequences so useful in basic research, their potency, stability and specificity, make them attractive as potential therapeutics.