Abstract
Unique DNA structures represent potential targets for small molecules, and provide a promising new avenue for drug development. However, attempts to rationally design small molecules that bind selectively to a particular DNA structure have been hampered by the lack of a rapid and convenient assay for structural selectivity. Determination of structure-selective ligand binding using competition dialysis is described in this unit. The competition dialysis assay is simple, straightforward, and rapid once stock solutions of the nucleic acid structures of interest have been prepared as described.