FAQ: How do I dilute the enzyme to 1 μM for in vitro reactions?

If planning to use higher concentration EnGen Sau Cas9 (NEB #M0654T) for in vitro digestion of DNA, the enzyme can be diluted to 1 μM in 1X NEBuffer 3.1 prior to the reaction assembly and used immediately. If the 1 μM dilution will be stored at -20°C, it should be diluted in the enzyme storage buffer: 20 mM Tris-HCl, 300 mM NaCl, 0.1 mM TCEP and 50% glycerol (pH 7.5 @ 25°C).