Human Duet siRNA Library - Ubiquitin Conjugation Subset 1

Screen with the two most reliable siRNA reagents available

Paired screening libraries of siGENOME and ON-TARGETplus siRNA for guaranteed silencing of human Cullin, E1, E2 and HECT E3 ubiquitin ligases.

Duet siRNA Libraries are paired libraries of  siGENOME and ON-TARGETplus siRNA SMARTpool reagents. The Human Duet Ubiquitin Conjugation Subset 1 contains siRNAs targeting human Cullin, E1, E2 and HECT E3 Ligases.

This siRNA library serves as a preliminary evaluation of the potential role of the ubiquitin system in processes under study. Assessment of effects of E1 and E2 enzymes will provide a reasonable idea as to whether components of the ubiquitin system are involved. Members of the HECT family of E3s differ from the large majority of known E3s (RING finger and RING finger-like) in functioning as catalytic intermediates in ubiquitin conjugation. Some of these events lead to proteasomal degradation while others are implicated in non-proteasomal ubiquitylation, including trafficking within the endosomal pathway.


  • Increase confidence in your RNAi screen with two guaranteed, highly functional SMARTpool siRNA reagents (see Figure 1, Supporting Data)
  • Screen the libraries side-by-side to move high confidence hits through the pipeline faster (see Figure 2, Supporting Data)
  • Use the libraries separately as a cost-effective way to obtain two guaranteed collections of highly potent siRNA reagents

siRNA Designs

Both siGENOME and ON-TARGETplus siRNA reagents utilize the same SMARTselection foundational elements for highly functional designs. ON-TARGETplus designs are additionally filtered for specificity-enhancing features that improve the potential for unique designs.

  • In 30% of genes (across the human genome), all eight siRNA sequences targeting a single gene are unique.
  • Only 5% of genes share four siRNA sequences across both product lines.
  • Even in cases of identical designs, it has been widely demonstrated that ON-TARGETplus specificity-enhancing modifications provide distinct and reduced off-target signatures and thus can be treated as unique silencing reagents.

Gene Targets and Pricing

For a complete list of target genes in these siRNA Libraries, please email Technical Support, or call 1-800-235-9880. International customers, please call 303-604-9499 or your local Sales Representative. 

Experimental considerations

For a thorough investigation of the ubiquitin pathway, you may also consider these additional libraries:

  • Deubiquitinating enzymes
  • Ubiquitin Conjugation Subset 2 - F-box, SOCS box E3 Ligases
  • Ubiquitin Conjugation Subset 3 - RING finger and RING finger-like E3 Ligases
Shipping ConditionAmbient
Stability at Recommended Storage ConditionsAt least 12 months
Storage Condition-20 C

Our siRNA knockdown guarantee

siGENOME and ON-TARGETplus siRNA reagents (SMARTpool and three of four individual siRNAs) are guaranteed to silence target gene expression by at least 75% at the mRNA level when used under optimal delivery conditions (confirmed using validated positive control and measured at the mRNA level 24 to 48 hours after transfection using 100 nM siRNA).

Note: Most siGENOME and ON-TARGETplus siRNA products are highly functional at 5 to 25 nM working concentration.

siGENOME and ON-TARGETplus SMARTpool reagents are highly potent

siGENOME and ON-TARGETplus SMARTpool reagents are highly potent

siGENOME and ON-TARGETplus SMARTpool reagents are highly potent

Figure 1 | Target mRNA knockdown in a screen with siGENOME and ON-TARGETplus SMARTpool siRNA reagents was highly effective, even at concentrations of 2 nM. In extended studies, ON-TARGETplus also was effective in reducing false phenotypes due to off-targets.

Duet siRNA libraries support high-confidence screening workflows

Duet siRNA libraries support high-confidence screening workflows

Duet siRNA libraries support high-confidence screening workflows

Figure 2 | Our products offer more guaranteed siRNA reagents than any other provider to enable the broadest range of siRNA screening strategies. By leveraging the high-efficiency silencing of market-leading siRNA reagents, the execution of a Duet siRNA screen with two unique SMARTpool siRNA reagents (siGENOME and ON-TARGETplus) increases overall primary hit quality and reduces follow-up experimental time and effort.


  1. B.D. Parsons, A. Schindler, D.H. Evans, E. Foley, A direct phenotypic comparison of siRNA pools and multiple individual duplexes in a functional assay. PLoS One. 4(12), e8471 (2009).
  2. M. Jiang, R. Instrell, B. Saunders, H. Berven, M. Howell, Tales from an academic RNAi screening facility; FAQs. Brief Funct. Genomics. 10(4), 227-237 (2011). [doi: 10.1093/bfgp/elr016]