The Cas9 (S. pyogenes) ELISA Kit can only detect Cas9 protein from S. pyogenes but not from S. aureus. The relationship between recombinant protein concentration and the absorbance at 450 nm using this ELISA kit is shown in the upper figure. The corresponding western blot (recombinant Cas9 from S. aureus in lane 1 and from S. pyogenes in lane 2) using a Cas9 (S. pyogenes) antibody is shown in the lower figure.