Delivery remains one of the last barriers for applying RNA interference (RNAi) in clinically relevant cell lines. Investigations at Dharmacon have led to the development of an innovative molecule for delivery in a wide variety of cell types. These modified siRNAs have been found to effectively silence target genes in cell types that are typically difficult to transfect using standard delivery methods. We present data for multiple cell types including SH-SY5Y (neuroblastoma), Jurkat (T-cells), and primary neurons. This technology, Dharmacon™ Accell™ siRNA reagents, allows for functional genomic studies in pertinent cell types. Moreover, in some instances, cells can be continuously dosed with these siRNAs, thus enabling knockdown of any target gene of interest for extended durations.