Bioassays: DNA–Protein Binding Force Chip (Small 21/2012)

A binding force chip translates differences in the interactions between ligands and nucleotide strands into fluorescence intensities with the help of molecular force balances. Such balances, developed by P. M. D. Severin and H. E. Gaub on page 3269, consist of tandem DNA duplexes bridging the gap between a microscope slide and an elastomer stamp, with one duplex acting as a target for ligand binding, the other as a reference. When the stamp is lifted off the glass, the force balance is stretched and the force in the molecular chain increases until the weaker of the two duplexes dissociates. Cover Art by Nanosystems Initiative Munich.