Available from Genetix are a range of microarray products suitable for screening the efficacy of short-interfering RNA (siRNA) molecules in RNA Interference (RNAi) studies
At the forthcoming RNAi Europe meeting in London (18-19 October 2004), Genetix will be demonstrating its QArrayMini microarrayer and Aquire microarray scanner with blue laser option that provides a perfect combination for carrying out RNAi optimisation experiments.
RNAi has been developed as a powerful molecular biology tool to achieve targeted gene silencing in cells. Double-stranded siRNA molecules (typically 20-25 nucleotides in length) can be introduced into mammalian cells by a variety of techniques (see Genetix Application Note: RNAi and Microarrays). Once inside the cell, these molecules interact with complementary target mRNA and specific proteins to form an RNA-induced silencing complex (RISC), which reduces or ablates the level of protein expression from the gene of interest.
It is usually necessary to test and optimise a variety of oligonucleotide sequences for their efficacy in silencing a given gene, which can be done in a parallel and high-throughput manner by microarraying.
The synthetic siRNA duplexes or the plasmids which are eventually processed into siRNA molecules in the cell can be arrayed with a matrix of lipid transfection reagents onto a microarray slide using the QArrayMini or QArray2.
The slide is then overcoated with a monolayer of adherent cells which subsequently become transfected upon contact with the arrayed spots.
In the case of an RNAi screen where the cell line is expressing a GFP fusion protein to the target gene, the efficacy of each siRNA molecule is assessed by the formation of plaques (non-fluorescent regions) in the lawn of fluorescent GFP-expressing cells.
Images of GFP fusion protein expressing cells can be acquired and analysed using the Genetix Aquire scanner with optional blue laser.
