of RNPs composed of recombinant, bacterially expressed Cas9 protein and synthetic RNA oligos corresponding to the CRISPR RNA (crRNA) and trans-activating CRISPR RNA (tracrRNA) components of the system. This has many advantages over other systems since the RNP complex is immediately active, when the concentration of any donor HDR template is the highest and is rapidly degraded over a period of around 12 h (Kim et al. 2014), reducing the potential for off-target mutagenesis and re-targeting after successful HDR. The lack of DNA plasmids also eliminates any chances of non-specific integration of DNA vectors into the genome.
