Figure EV3. FRET efficiency histograms of fluctuating and static Cas9 molecules.

• A–D
  FRET efficiency histograms of fluctuating D435C–E945C (A), static D435C–E945C (B), fluctuating S867C‐N1054C (C), and static S867C‐N1054C (D). The numbers of measured molecules are summarized in Table EV1. The top, middle, and bottom panels show data acquired in the absence of the nucleic acids, in the presence of 200 nM sgRNA, and in the presence of 200 nM sgRNA and 200 nM target DNA, respectively. All of the data in this figure were obtained in assay buffer containing 2 mM MgCl₂.