Analysis of DNA-Protein Interactions Using PAGE: Band-Shift Assays

The band-shift assay using polyacrylamide gel electrophoresis is a powerful technique used to investigate DNA–protein interactions. The basis of the method is the separation of free DNA from DNA–protein complexes by virtue of differences in charge, size, and shape. The band-shift assay can be used to determine thermodynamic and kinetic binding constants and also to analyze the composition and stoichiometries of DNA–protein complexes.