Research of methods to detect genomic mutations induced by CRISPR/Cas systems

The indel-forming non-homologous end joining (NHEJ) pathway repairs double strand breaks in mammalian genomes, resulting in mutation formation following genome editing. Common techniques employed to identify these mutations include the amplified fragment length polymorphism (AFLP) and SURVEYOR assays, which are time consuming, laborious, and only offer a low level of sensitivity. An alternative to these approaches, which is examined in this study, is based on the quantitative PCR high-resolution melting (qPCR-HRM) curve analysis technique and offers simple implementation, is capable of handling large sample sizes, takes no more than 90 min, and produces sensitive results. Using the newly discovered RNA-guided CRISPR/Cas systems, the IL2RG and EMX1 genes were edited in the human 293T cell line in order to compare the mutation detection accuracies of the aforementioned methods. Genomic mutations were simulated by mixing mutated DNA fragments with normal fragments along a concentration gradient. The results of this comparative study showed that the HRM approach was both reproducible and accurate.