Figure 3. Purification of rSaCas9 by affinity chromatography
The rSaCas9 apoenzyme was purified via its C-terminal Strep-tag II by affinity chromatography on a Strep-Tactin matrix. Aliquots of 0.5 µl (IVT pool, pellet, load, flow through, wash) or 6.5 µl (EF#1 – EF#6) of the different fractions were separated by SDS–PAGE, and the proteins were visualized by staining with Coomassie Brilliant Blue. Purified rSaCas9 migrates with an apparent molecular mass of 130 kDa.