A unique siRNA reagent for neuronal, immune, primary, stem, and other difficult-to-transfect cells

To achieve robust silencing of a target gene with siRNA, the first critical step is efficient delivery of siRNA into the cells of interest. However, many neuronal, immunological, primary, and stem cells are refractory to traditional lipid or electroporation methods, so are at a disadvantage for using standard siRNA reagents. Luckily, we have a unique solution for these issues: Dharmacon Accell siRNA.

Accell siRNA combines our expertise in algorithmic siRNA design with a patented chemical modification pattern from our advanced synthesis chemistry.

The novel passive-entry mechanism of Accell has been demonstrated to be successful in numerous difficult-to-transfect cell types without any need for transfection reagents, lentiviral vectors, or electroporation/nucleofection instruments:

  • Accell siRNA was used to decrease the level of parkin protein by 80% in mouse primary cortical neurons. 1
  • Lopez-Castejon et al achieved a 60% decrease of UCh67 in THP-1 monocytes as measured by western blot. 2
  • In an arrayed Accell siRNA screen  primary human T cells, Accell uptake was measured by flow cytometry to be delivered into virtually 100% of cells, with approximate reduction of 70% of target genes. 3
  • Mitchnick et. al. applied Accell siRNA to knockdown epigenetic enzymes in specific brain regions and impaired memory function in rats. 4

Another advantage to the Accell passive delivery strategy is that reapplication of siRNA can be used without the cytotoxic effects related to lentiviral or lipid-based products. This allows one to achieve long-term gene knockdown for studies that may need extended duration of silencing (up to 30 days tested in Dharmacon labs). Such approaches can be beneficial to the researcher who needs to accurately assess the contribution of a protein with a longer half-life than is impacted with traditional siRNA methods (4-6 days). A published example of this approach in rat primary cortical neurons achieved robust target silencing after 10 days with Accell siRNA treatments at 3 day intervals. 5

Interested in getting started with Accell? If not, Accell Control Kits are an economical way to optimize serum amount (<3% recommended) and delivery conditions.

Get started with Accell siRNA today! »


  1. H. Mortiboys, J. Aasly, et al. Ursocholanic acid rescues mitochondrial function in common forms of familial Parkinson's disease. Brain 136, 3038-3050 (2013).
  2. G. Lopez-Castejon, N. M. Luheshi, et al. Deubiquitinases Regulate the Activity of Caspase-1 and Interleukin-1β Secretion via Assembly of the Inflammasome. J. Biol. Chem 288, 2721 – 2733 (2103).
  3. Freeley M, Derrick E, et al. RNAi Screening with Self-Delivering, Synthetic siRNAs for Identification of Genes That Regulate Primary Human T Cell Migration. J. of Biomolecular Screening 20, 943 – 956 (2015).
  4. Mitchnick, K. A., Creighton, S., O'Hara, M., Kalisch, B. E. and Winters, B. D. (2015), Differential contributions of de novo and maintenance DNA methyltransferases to object memory processing in the rat hippocampus and perirhinal cortex – a double dissociation. Eur J Neurosci, 41: 773–786. doi:10.1111/ejn.12819
  5. P. Mergenthaler et al., Mitochondrial hexokinase II (HKII) and phosphoprotein enriched in astrocytes (PEA15) form a molecular switch governing cellular fate depending on the metabolic state. PNAS USA. 109(5), 1518-1523 (31 January 2012).

Additional Resources 

Poster: Knockdown of p53 by Accell self-delivering siRNA causes inhibition of p53-dependent DNA damage response in IMR-32 neuroblastoma cell line and ß-amyloid toxicity in rat cortical neurons
  • Poster describing use of Accell siRNA for high content screening in IMR-32 neuroblastoma cells and primary rat cortical neurons.
Application Note: A Novel ex vivo Application of RNAi for Neuroscience
  • A large number of patients worldwide suffer from neuronal disorders such as Alzheimer’s, Parkinson’s, and Huntington’s diseases.