The crRNAs probes are designed to cut specific sequences, but the cleavage could sometimes be incomplete. In the Excision approach, we recommend using two cuts upstream of the ROI targeting the (+) strand, and two downstream targeting the (-) strand for redundancy in case one or more crRNAs yield incomplete cleavage.

More information can be found in the Targeted, amplification-free DNA sequencing using CRISPR/Cas info sheet.