SpCas9 sgRNA Modifications

Synthego's SpCas9 sgRNA standard modifications bear 2'-O-methyl analogs (OMe) on the first and last three bases and 3' phosphorothioate internucleotide linkages (PS) between the first three and last two bases. Our SpCas9 modified sgRNA has a total of 6 OMe modified nucleotides and 5 PS bonds.

We generally recommend ordering chemically modified sgRNA for cell culture and in vivo experiments with SpCas9 for the following reasons:   

• Increased stability and protection from exonucleases

• Overall improved editing efficiency (Hendel et al., 2015, PMID: 26121415)

• Reduced innate immune response (Kim et al., 2018, PMID: 29472270; Weinert et al., 2018, PMID: 30011268) compared to in vitro transcribed sgRNAs
• Reduced off-targets compared to plasmid or viral delivery (Cameron et al., 2017, PMID: 28459459)