A study released today in Nature Biotechnology that found large deletions and complex rearrangements after CRISPR-Cas9 gene editing led to a $300 million drop in valuation for the three largest gene editing companies. The team from the Welcome Sanger Institute used long range PCR to amplify monoclonal cell lines derived from a standard gene editing in mouse embryonic stem cells. Using various gRNAs, they detected deletions as large as 9.5 kb in up to three-quarters of cell lines. Additionally, some cell lines contained multiple deletions and insertion events. An additional 6% of cell lines failed to amplify altogether, suggesting much larger deletions or translocations that they couldn’t detect in this study. And importantly, they only checked the target region – maybe similar rearrangements took place at off-target sites where Cas9 caused double stranded breaks.
Bionano mapping was MADE for this kind of studies. Our extremely long molecule imaging detects heterozygous deletions, insertions and translocations with higher sensitivities than any sequencing based method, and does so genome wide for a low cost. Whether your gene editing experiments involve plants or animals, cell lines, or gene therapy, you need Bionano to show you the true structure of the genome after CRISPR, and the wanted and unwanted rearrangements.