Near 100% genome editing efficiency with a one-step all RNA prime editing system in a human reporter iPSC line

CRISPR/Cas9 nucleases offer powerful tools for genome editing but can cause unintended mutations at the target site due to the creation of double-stranded DNA breaks. Prime editing (PE) is arguably a safer technology as it relies on the creation of single-strand DNA nicks and avoids possible indels. Despite its precision, current PE systems are limited by relatively low editing efficiency in non-immortalized cells. Here, we optimized prime editing in human induced pluripotent stem cells (hiPSCs) using a fluorescence-based assay to achieve near-complete editing of a BFP transgene. Using an all-RNA approach, precise prime editing of a single nucleotide variant was observed in >95% of cells with minimal unintended edits at the target site.