Accell siRNA

Accell siRNA

Product Overview

Accell siRNA achieves what no other product can claim: delivery into difficult-to-transfect cells without additional reagents, virus, or instruments. Achieve guaranteed gene silencing in cells that had been beyond the reach of conventional RNAi methods due to toxicity from transfection reagents, electroporation, or undesirable viral responses.


  • Novel, patented siRNA modifications facilitate passive uptake, protection against nuclease degradation, specificity, and knockdown efficiency
  • Accell self-delivering siRNA enters cells without the need for transfection reagents, viral vector transduction, or instruments (nucleofection or electroporation)
  • Low toxicity enables extended-duration silencing from multiple doses – up to 30 days!

View our researcher-submitted data gallery and review published references that demonstrate proven performance in difficult-to-transfect cell types

  • Immunological cells – Jurkat cells, primary T cells, lymphocytes, mononuclear cells (PBMC), macrophages
  • Neuronal cells – primary neurons, glioma cells, organotypic brain slices
  • Primary cells – fibroblasts, cardiomyocytes, β-islet cells
  • In vivo models – brain delivery, dermal (skin) delivery, periodontal model

Experimental considerations

This breakthrough in siRNA delivery requires no transfection reagent, but has some unique application requirements.

  • Accell siRNA works at a higher concentration than conventional siRNA; recommended 1µM working concentration.
  • Delivery may be inhibited by the presence of BSA in serum. Optimization studies with serum-free media formulations (Accell Delivery Media) or < 2.5% serum in standard media is recommended.
  • Full-serum media can be added back after 48 hours of incubation, optimal mRNA silencing is typically achieved by 72 hours, or up to 96 hours for protein knockdown.
  • Accell siRNA Gene Search

    Begin a gene search to place an order for human, mouse, or rat Accell siRNA.

  • Human siRNA Libraries

    Find the predefined gene family, including Druggable genes or Whole Genome, that’s right for your discovery efforts.

  • Mouse siRNA Libraries

    A wide selection of predefined siRNA libraries, including the most up-to-date Whole Mouse genome collection available.

  • Accell siRNA Controls

    Effectively optimize Accell siRNA delivery conditions with fluorescent or unlabeled positive and negative controls. Kits of validated controls available.

  • Cherry-pick RNAi Libraries

    Fast and easy online configuration and ordering of plated siRNA & microRNA reagents targeting your genes of interest.

  • Custom siRNA Synthesis

    No pre-designed product to fit your needs? Use our online design tools and extensive synthesis options to create a custom siRNA specific for your application.

Product Formats

  • SMARTpool:

    • A mixture of 4 siRNA provided as a single reagent; providing advantages in both potency and specificity.
  • Set of 4:

    • A convenient option for purchasing aliquots of all 4 individual siRNAs targeting a single gene.
  • Set of 4 Upgrade:

    • Discounted price on the Set of 4 based on a concurrent or prior purchase of the SMARTpool reagent for the same gene.
  • Individual siRNAs:

    • Select 1, 2, 3 or 4 individual siRNAs per gene.

Our siRNA knockdown guarantee

Accell 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 optimized conditions as defined in this featured article.

Learn more about the Accell siRNA knockdown guarantee »

Ordering Guidelines

Approximate # reactions (wells) at 1 µM siRNA concentration (assuming no loss from pipetting)

96-well plate
(100 uL total reaction volume)
24-well plate
(500 uL total reaction volume)
12-well plate
(1000 uL total reaction volume)
2 20 4 2
5 50 10 5
10 100 20 10
20 200 40 20

Due to the unique nature of Accell siRNA delivery, it requires a higher working concentration than conventional siRNAs. This table provides the approximate number of reactions (wells) at recommended 1μM Accell siRNA working concentration in different plate formats (assuming no loss from pipetting).

Product Line Selection

Which siRNA is right for you?

Dharmacon offers four complete pre-designed product lines across human, mouse and rat genomes. Use the table below to assist you in determining the right siRNA product line for your needs.

Cost-effective, efficient silencing High specificity for reduced off-targets & efficient silencing Highly specific knockdown of long noncoding RNA (lncRNA) Target silencing in difficult-to-transfect cells
siGENOME siRNA ON‑TARGETplus siRNA Lincode siRNA Accell siRNA
predesigned for Human, Mouse and Rat protein-coding genes
predesigned for Human and Mouse long noncoding RNA (lncRNA)
Recommended for transfectable mammalian cells in culture
Recommended for neuronal, suspension, primary and other difficult-to-transfect cells
Recommended transfection reagent DharmaFECT transfection reagent DharmaFECT transfection reagent DharmaFECT transfection reagent None required
Available as SMARTpool reagent
Available as four individual siRNAs
Guaranteed knockdown by SMARTpool and 3 of 4 siRNAs
Sense strand is modified to prevent interaction with RISC and favor antisense strand uptake Selective application when thermodynamic analysis indicates it necessary for favorable antisense RISC loading
Antisense strand seed region is modified to destabilize off-target activity and enhance target specificity
Modifications to facilitate cellular uptake without separate transfection reagents
Stabilizing modifications to prevent nuclease-mediated degradation
Sequence information provided with purchase

Data Gallery

Researchers have submitted the following figures to show off their great gene silencing results in their difficult-to-transfect cells using Accell siRNA. If you have data to showcase, fill out this brief form and you will receive instructions on how to submit your data! New data will be added regularly, so check back often!

Accell siRNA Resources