Some vendors score gRNA sequences for off-target effects – we show that score when we can
As with other nucleotide-targeted experimental methods (e.g. RNAi), off-target effects are a valid concern when designing a research project. Off-target effects can arise from complementarity of the gRNA sequence with other parts of the genome (particularly in the gRNA seed region), leading to undesired effects on the genome and protein expression. Some vendors on BenchSci score their gRNAs based on various criteria and we have included those scores on product pages when possible. Three such vendors are Thermo Fisher Scientific, Sigma Aldrich, and Integrated DNA Technologies.
Thermo Fisher Scientific – Thermo Fisher scores gRNA out of 100 based on predicted binding efficiencies and other sequence factors.
Sigma Aldrich –gRNA are given two scores out of 100: an Efficiency score based on work published by Doench, Fusi et al (2016), and a Specificity score based on Hsu et al (2013).
Integrated DNA Technologies – gRNA are given two scores out of 100: an On-Target score based on the predicted editing performance at the gene of interest, and an Off-Target score where a higher value indicates a lower likelihood of off-target effects.
If there are other gRNA scoring systems you'd like us to implement, we'd love to hear from you!