Quantifying screening ion excesses in single-molecule force-extension experiments

• Published in: Physical review letters Vol. 109; no. 4; p. 048301
• Main Authors: Landy, Jonathan, McIntosh, D B, Saleh, O A
• Format: Journal Article
• Language: English
• Published: United States 27.07.2012
• Subjects: Anions - chemistry; Cations - chemistry; DNA - chemistry; DNA, Single-Stranded - chemistry; Electrolytes - chemistry; Models, Chemical

We derive a thermodynamic identity that allows one to infer the change in the number of screening ions that are associated with a charged macromolecule as the macromolecule is continuously stretched. Applying this identity to force-extension data on both single-stranded and double-stranded DNA, we f...