Mechanism of RNAi

Synthetic siRNA. The sense strand
is indicated in red, anti-sense strand
in green.

The RISC complex (RNA induced silencing
complex) loads the antisense
strand to produce the desired RISC
complex. Note that the sense strand may
be loaded as well resulting in most of
the off-target effects.

The cleavage-competent, sequence
specific RISC cleaves the target mRNA.

This results in a down-regulation of
protein production.
Note: stable proteins (long half-life) are
more restistant to knock-down by RNAi.
Analysis of protein level is crucial.