Presently whole genome sequencing of each genome edited clone is not feasible. Rather, we suggest that at least two independent clones be recovered for each genome editing experiment. This will help to control for potential confounding effects of off-target mutations, although our whole genome sequencing data shows that some off-target sites are recurrently mutated in independent clones. Therefore it is optimal to use two independent gRNAs. Rescue of mutant cells by transient cDNA expression is an alternative strategy to control for off-target mutation3.
