Genome-wide specificity assessment of CRISPR-Cas nucleases with Tag-seq

CRISPR-Cas systems enable the rapid and flexible manipulation of genomes in a targeted manner but also induce unexpected off-targets. And, a facile and efficient method for off-target cleavages profiling remains challenging. Here we presented Tag-seq, an improved method built on GUIDE-seq, which enables rapid and convenient profiling of DNA double-strand breaks (DSBs) by incorporating the optimized designed dsODN, adapters, and PCR primers and the optimized procedure for library preparation. Using Tag-seq, we successfully determined the cleavage specificity of Cas9 variants and Cas12a/Cpf1, and profiled the integration sites of exogenous genes introduced by the Sleeping Beauty transposon. In this study, we demonstrated that Tag-seq provides an alternative, facile and efficient approach for genome-wide identification of DSBs.