Extended Data Fig. 1: Schematic representation of the high-throughput evaluation of pegRNA activities.

A lentiviral plasmid library was prepared from a pool of oligonucleotides that contained pairs of pegRNA-encoding sequences and corresponding target sequences. Next, HEK293T cells were transduced with lentivirus generated from the plasmid library to construct a cell library and untransduced cells were removed by puromycin selection. This cell library was then transfected with a plasmid encoding NG-PE2, and untransfected cells were removed by blasticidin selection. Five days after the transfection, genomic DNA was isolated from the cells, PCR-amplified, and subjected to deep sequencing to determine prime editing efficiencies.