Recombinant Streptococcus pyogenes Cas9 nuclease, purified from E.coli, is a powerful tool for genome editing. The nuclease can also be applied to the field of molecular diagnosis. This product has undergone codon optimization, nuclear localization signal (NLS) design, and optimization of E. coli expression and purification. This product has been filed with the FDA Drug Master Files (DMF) and is assigned DMF #036578.