The Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) Type II system is currently the most commonly used RNA-Guided Endonuclease technology for genome engineering. There are two distinct components to this system: (1) a guide RNA and (2) an endonuclease, in this case the CRISPR associated (Cas) nuclease, Cas9. The gRNA/Cas9 complex is recruited to the target sequence by the base-pairing between the gRNA sequence and the complement to the target sequence in the genomic DNA. Fo