We couldn’t find your input sequence in the human genome. You may also receive this error message if your input sequence appears often in the human genome, e.g. because it is very short. Please check your target sequence and try again, or email us at firstname.lastname@example.org.
Risk score is calculated based on sequence similarity throughout the genome. Risk scores range from 0 (best; no matches at any position within 20bp 5’ to GG anywhere in the genome) to 57 (exact match across the entire 20-mer). We recommend selecting gRNAs with Risk Score <49 to avoid the possibility of off-target binding.
See where each gRNA sequence aligns to the FASTA sequence you input. If you prefer to see gRNA results displayed as alignments to the human reference genome, please go back and search using "Option 1: Search By Gene Name"
A Potential off-target site may be displayed when the risk score is 0 if the PAM sequence is not present. Because the PAM is required for Cas9 targeting, these gRNA sequences are expected to provide high-specificity binding despite some similarity to off-target loci in the protospacer region.