Multiple publications confirm that higher siRNA concentrations lead to increased off-target effects 1,2.
The need to design more potent siRNAs that can be used at lower concentrations was therefore a key driver in our siRNA design algorithm improvement efforts.

Silencer Select siRNAs Provide Up to 100X Higher Potency Compared to Other siRNAs.
Silencer Select siRNAs to 10 different targets and siRNAs from two other suppliers to the same 10 different targets were individually transfected into HeLa cells in triplicate at the indicated siRNA concentration. mRNA knockdown levels were tested 48 h later as described in Figure 1. Average percent mRNA remaining is shown for each set of siRNAs.

Silencer Select siRNAs

  • Are up to 100X more potent than competitor siRNAs
  • Can be routinely transfected at ≤5 nM and retain their silencing power
  • Result in fewer off-target effects when used at these lower concentrations
  • Cost less per experiment than siRNAs used at higher concentrations


  1. Semizarov D, Frost L, Sarthy A, Kroeger P, Halbert DN, Fesik SW (2003) Specificity of short interfering RNA determined through gene expression signatures. Proc Natl Acad Sci USA 100(11):6347–6352.
  2. Jackson AL, Bartz SR, Schelter J, Kobayashi SV, Burchard J, Mao M, Li B, Cavet G, Linsley PS (2003) Expression profiling reveals off-target gene regulation by RNAi. Nat Biotechnol 21(6):635–637.
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