Chemically Synthesized Modified Guide RNAs Enhance Crispr/Cas Genome Editing

Using an advancement in RNA synthesis technology (Dellinger et al. J. Am. Chem. Soc. 2011, 133, 11540–11556), we find it straightforward to chemically synthesize RNAs of more than 100 nt in length and to incorporate modified nucleotides at any position. Using this technology, we have demonstrated that chemical alterations to synthesized single guide RNAs (sgRNAs) enhance genome editing efficiency in human primary T cells and CD34+ hematopoietic stem and progenitor cells (Hendel et al. Nat. Biotech. 2015 doi:10.1038/nbt.3290). Here, we extend this work characterizing the performance of chemically modified sgRNAs for genome editing in additional cell types including human primary cells (e.g. Fibroblasts, hepatocytes) and induced pluripotent stem cells. The ability to chemically synthesize high quality sgRNAs in a scalable manner enables their widespread application in all phases from basic research to therapeutic use.