Titration of lac operator DNA with lac repressor protein.
Titration of lac operator DNA with lac repressor protein. Increasing amounts of lac repressor protein were mixed with 40 ng of lac operator DNA, incubated for 20 minutes and then separated on a 6% nondenaturing polyacrylamide gel. The gel was stained with SYBR® Green EMSA stain (green) followed by SYPRO® Ruby EMSA stain (red), components of the Electrophoretic Mobility-Shift Assay Kit (Cat No. E33075). After each staining, the image was documented using an FLA-3000 laser-based scanner (Fuji) and the digital images pseudocolored and overlaid. Yellow bands indicate areas stained with both stains.