Nested CRISPR enables efficient genome editing using long DNA fragments

CRISPR is a technique that is revolutionizing biomedical research through high-precision genome editing. However, even though it allows the creation or correction of mutations consisting of a single or few nucleotides with relative ease, it still possesses limitations for larger fragments of DNA in the genome. For instance, the genomic insertion of a gene that produces a fluorescent protein such as the widely-used GFP suffers from poor efficiency and involves complicated cloning steps.