Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Video

Updated: May 18, 2026

Force Spectroscopy of Single Protein Molecules Using an Atomic Force Microscope
06:45

Force Spectroscopy of Single Protein Molecules Using an Atomic Force Microscope

Published on: February 28, 2019

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

Jonathan Landy1, D B McIntosh, O A Saleh

  • 1Materials Department, University of California, Santa Barbara, California 93106, USA. landy@mrl.ucsb.edu

Physical Review Letters
|September 26, 2012
PubMed
Summary
This summary is machine-generated.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Evaluation of 13,466 Fecal Immunochemical Tests in Patients Attending Primary Care for High- and Low-Risk Gastrointestinal Symptoms of Colorectal Cancer.

Digestive diseases and sciences·2022
Same author

Charge Renormalization for Ellipsoidal Macroions.

ACS macro letters·2022
Same author

Clostridium difficile and cystic fibrosis: management strategies and the role of faecal transplantation.

Paediatric respiratory reviews·2017
Same author

Tight junctions in inflammatory bowel diseases and inflammatory bowel disease associated colorectal cancer.

World journal of gastroenterology·2016
Same author

General Differential Contact Identities for Macromolecules.

Physical review letters·2015
Same author

Innate immune factors in the development and maintenance of pouchitis.

Inflammatory bowel diseases·2014
Same journal

Erratum: Bacterial Turbulence at Compressible Fluid Interfaces [Phys. Rev. Lett. 136, 138301 (2026)].

Physical review letters·2026
Same journal

Unveiling Light-Quark Yukawa Flavor Structure via Dihadron Fragmentation at Lepton Colliders.

Physical review letters·2026
Same journal

Adaptable Route to Fast Coherent State Transport via Bang-Bang-Bang Protocols.

Physical review letters·2026
Same journal

Topological Transition and Emergence of Elasticity of Dislocation in Skyrmion Lattice: Beyond Kittel's Magnetic-Polar Analogy.

Physical review letters·2026
Same journal

Pound-Drever-Hall Method for Superconducting-Qubit Readout.

Physical review letters·2026
Same journal

Coupling a ^{73}Ge Nuclear Spin to an Electrostatically Defined Quantum Dot in Silicon.

Physical review letters·2026
See all related articles

Stretching charged polymers like DNA alters associated ion counts, revealing complex dependencies on salt concentration and polymer rigidity. Single-stranded DNA shows a significant ion decrease when stretched.

Area of Science:

  • Biophysics
  • Physical Chemistry
  • Polymer Science

Background:

  • Charged macromolecules in solution are surrounded by counterions and coions, forming an ionic atmosphere.
  • The interaction between charged polymers and ions is crucial for understanding their behavior in biological systems and synthetic applications.
  • Previous studies have explored ion binding to DNA, but dynamic changes during mechanical stretching remain less understood.

Purpose of the Study:

  • To derive a thermodynamic identity for quantifying ion number changes during macromolecule stretching.
  • To investigate how stretching affects ion association with single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA).
  • To correlate ion number changes with polymer properties like salt concentration and intrinsic rigidity.

Main Methods:

More Related Videos

Investigating Single Molecule Adhesion by Atomic Force Spectroscopy
09:48

Investigating Single Molecule Adhesion by Atomic Force Spectroscopy

Published on: February 27, 2015

Investigating Receptor-ligand Systems of the Cellulosome with AFM-based Single-molecule Force Spectroscopy
11:34

Investigating Receptor-ligand Systems of the Cellulosome with AFM-based Single-molecule Force Spectroscopy

Published on: December 20, 2013

Related Experiment Videos

Last Updated: May 18, 2026

Force Spectroscopy of Single Protein Molecules Using an Atomic Force Microscope
06:45

Force Spectroscopy of Single Protein Molecules Using an Atomic Force Microscope

Published on: February 28, 2019

Investigating Single Molecule Adhesion by Atomic Force Spectroscopy
09:48

Investigating Single Molecule Adhesion by Atomic Force Spectroscopy

Published on: February 27, 2015

Investigating Receptor-ligand Systems of the Cellulosome with AFM-based Single-molecule Force Spectroscopy
11:34

Investigating Receptor-ligand Systems of the Cellulosome with AFM-based Single-molecule Force Spectroscopy

Published on: December 20, 2013

  • Derivation of a novel thermodynamic identity relating ion number change to stretching.
  • Experimental force-extension measurements on individual ssDNA and dsDNA molecules.
  • Analysis of force-extension data in conjunction with the derived thermodynamic identity.

Main Results:

  • The number of polymer-associated ions changes non-trivially with stretching.
  • Ion association is dependent on both bulk salt concentration and the polymer's bare rigidity.
  • Single-stranded DNA exhibits a pronounced decrease in associated ions upon stretching compared to double-stranded DNA.

Conclusions:

  • The derived thermodynamic identity provides a powerful tool for studying ion-polymer interactions under mechanical stress.
  • Stretching induces significant, sequence-dependent (ssDNA vs. dsDNA) changes in the ionic environment around polymers.
  • These findings offer insights into polyelectrolyte behavior and can inform the design of novel biomaterials and nanodevices.