Dr. Thomas Gaj has developed a novel prime editor based on a Staphylococcus aureus Cas9 ortholog. Furthermore, he has developed split intein versions of the prime editing tools that are small enough to be dual-delivered in adeno-associated viruses, an FDA-approved vehicle for therapeutic use. This invention has been shown to improve targeting capability of the prime editors by several fold. Prime editors have recently shown great promise as gene editing tools with greater specificity and fewer off-target effects than existing CRISPR-Cas based methods. This technology has potential as a research tool as well as a therapeutic strategy.