Skip to main content
. 2019 Jun 13;17:761–769. doi: 10.1016/j.csbj.2019.06.007

Fig. 1.

Fig. 1

Overview of CRISPR/Cas9 gene editing system and DNA repair mechanisms. When complexed with a sgRNA, Cas9 will cleave double stranded DNA at a specific site directed by the target sequence and PAM of the sgRNA. Once the DNA is cleaved, two DNA repair pathways, NHEJ and HDR, occur and may alter the genome of the cell. In NHEJ, insertions or deletions of nucleotides may occur at the cleavage site; alternatively if multiple DSBs are generated, repair can occur between different fragments. During HDR homologous recombination occurs at the loci adjacent to the DBS using a DNA template.