RNA interference via synthetic small interfering RNA (siRNA) is the preferred choice for fast but reliable loss-of-function studies. Broadly useful across many applications and in any cell line, siRNA offers a straightforward and widely cited technique for functional gene silencing. For over 20 years, Dharmacon has remained the most trusted name in high quality siRNA design and synthesis.
Select a predesigned siRNA product line or design your own siRNA with custom modifications.
Our siRNA knockdown guarantee
The ON-TARGETplus, Accell and siGENOME siRNA lines are guaranteed* to effectively silence target gene expression by at least 75% at the mRNA level.
DharmaFECT transfection reagents
Not sure where to start?
Knockdown long, non-coding RNA genes with specialized siRNA, modified to ensure specificity.
Custom siRNA design
Use our siDESIGN Center to create a custom siRNA to any gene for any species or provide your own sequence for custom modified siRNA synthesis
Reducing off-targets maximizes specificity
A successful siRNA knockdown experiment must be both effective and specific. Horizon’s SMARTselection design algorithm (used for ON-TARGETplus, Accell, siGENOME and Lincode siRNA) provides a high degree of confidence that the targeted gene will be the only one silenced.
The primary source of siRNA-mediated off-targets is the seed region (nucleotides 2-7), which uses the microRNA pathway to induce non-specific gene silencing via interactions within the 3' UTR. Incorporating comprehensive bioinformatic strategies such as seed region filters and seed frequency analysis within the SMARTselection design strategy minimizes microRNA-like off-target activity for improved specificity.
Pooling siRNA improves effectiveness
The SMARTpool (available for ON-TARGETplus, Accell, siGENOME and Lincode siRNA) combines four gene-specific siRNAs into a single reagent pool. Research has shown that pooled siRNAs:
- Improve the likelihood of effective gene silencing
- Minimize sequence-specific off-targeting by lowering the relative concentration of each siRNA
- Better mimic the natural RNAi pathway
- Reduce false negatives caused by inaccessible binding sites
Which siRNA is right for you?
Horizon offers multiple predesigned product lines across human, mouse and rat genomes. Use the table below to determine the optimal siRNA for your needs.
|ON-TARGETplus siRNA Chemically modified for enhanced specificity||Accell siRNA Self delivering siRNA||siGENOME siRNA Cost-effective, efficient silencing||Lincode siRNA Knockdown long non-coding RNA|
|Recommended for neuronal, suspension, primary and other difficult-to-transfect cells|
|Recommended transfection reagent||DharmaFECT transfection reagent||None required||DharmaFECT transfection reagent||DharmaFECT transfection reagent|
|Available as individual siRNA and SMARTpool formats|
|Guaranteed knockdown by SMARTpool and 3 of 4 siRNAs|
|Sense strand modifications to prevent interaction with RISC and favor antisense strand uptake|
|Antisense strand seed region modifications to destabilize off-target activity and enhance target specificity|
|Modified to facilitate cellular uptake without separate transfection reagents|
|Stabilizing modifications to prevent nuclease-mediated degradation|
|Sequence information provided with purchase|
|Search ON-TARGETplus||Search Accell||Search siGENOME||Search Lincode|
Scale up your siRNA experiment
Run your own siRNA knockdown screen at any scale with our predesigned and custom library options.
Human siRNA libraries
Mouse siRNA libraries
Cherry-Pick custom library builder
Need help with a new RNAi technique? We offer live scientific support as well as an extensive collection of technical resources to help get you started!
Speak with an RNAi expert
siRNA technical resources
Video: Basic siRNA resuspension
siRNA by Dharmacon selection guide
Choose the optimal siRNA product line and format for your experiment