Targeting double-strand break indel byproducts with secondary guide RNAs improves Cas9 HDR-mediated genome editing efficiencies

Abstract

Programmable double-strand DNA breaks (DSBs) can be harnessed for precision genome editing through manipulation of the homology-directed repair (HDR) pathway. Here the authors report the development of the double tap - double tap implements secondary gRNAs which target Cas9 to common indel sequences and provides a second chance at HDR.