Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Chemical Shift: Internal References and Solvent Effects

Chemical Shift: Internal References and Solvent Effects

In an NMR sample, precise measurement of the absolute absorption frequencies of nuclei is difficult. A standard internal reference compound is added, and the frequency difference between the reference signal and sample signals is measured.
The internal reference compound generally used in NMR spectroscopy is tetramethylsilane (TMS). TMS is preferred because it is chemically inert, soluble in NMR solvents, and easily removable. Also, the highly shielded methyl protons in TMS yield an intense...

Insensitive Nuclei Enhanced by Polarization Transfer (INEPT)

Insensitive Nuclei Enhanced by Polarization Transfer (INEPT)

Insensitive Nuclei Enhanced by Polarization Transfer (INEPT) is an advanced Nuclear Magnetic Resonance (NMR) technique specifically designed to detect and enhance the signals of low-abundance nuclei, such as carbon-13 and nitrogen-15, in small molecules. The fundamental principle behind INEPT is the transfer of polarization from a more abundant and highly polarizable nucleus, typically hydrogen-1, to the low-abundance nucleus of interest. This process effectively boosts the NMR signal of the...

You might also read

Related Articles

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

Sort by

Same author

NMR of Fully and Partially <sup>13</sup>C-Enriched Biomass Enhances Pendent Group Structural Characterization.

Analytical chemistry·2026

Same author

Protonated Structure of EmrE Reveals C-terminal Tail Gating Mechanism.

bioRxiv : the preprint server for biology·2026

Same author

Breakdown products of the fungicide Fludioxonil may account for observed environmental impact: potential implications for human health.

PeerJ·2026

Same author

Intrinsic conformational equilibria position arrestin-2 for activation.

Protein science : a publication of the Protein Society·2026

Same author

Fast folding of anthrax lethal factor N-terminal domain independent of proline isomerization.

Biophysical journal·2026

Same author

Proton hopping and secondary gating reveal a universal transport mechanism in a minimal bacterial transporter EmrE.

Biophysical journal·2026

Same journal

Efficient Syngas Photoproduction Enabled by Electronic Engineering of Co-Immobilized Imine COFs.

Angewandte Chemie (International ed. in English)·2026

Same journal

Pathway Controlled Phase Separation of Minimal Building Blocks Utilizing a Dissociative Chemical Transformation.

Angewandte Chemie (International ed. in English)·2026

Same journal

Interaction Hierarchy and Polymorphic Structure-Property Dynamics in Luminescent Molecular Crystals.

Angewandte Chemie (International ed. in English)·2026

Same journal

The Role of Zn-Hf Site Proximity and Oxygen Vacancies for Methanol Formation Over ZnHfO<sub>x</sub> Catalysts Under CO<sub>2</sub> Hydrogenation Conditions.

Angewandte Chemie (International ed. in English)·2026

Same journal

Breaking the Linear Scaling Relationship: Bioinspired Electronic Coupling in S-Bridged Fe-Fe Dual Sites for Efficient Oxygen Reduction.

Angewandte Chemie (International ed. in English)·2026

Same journal

Programming Bio-Bio Electronic Interfaces for Light-Driven Interspecies Electron Transfer.

Angewandte Chemie (International ed. in English)·2026

See all related articles

Search research articles

Related Experiment Video

Updated: May 21, 2025

Dissolution Dynamic Nuclear Polarization Instrumentation for Real-time Enzymatic Reaction Rate Measurements by NMR

Dissolution Dynamic Nuclear Polarization Instrumentation for Real-time Enzymatic Reaction Rate Measurements by NMR

Published on: February 23, 2016

In Situ Light-driven pH Modulation for NMR Studies.

Aarav Barde¹, Ruixian Han², Martin A Olson¹

¹Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA.

Angewandte Chemie (International Ed. in English)

|March 22, 2025

Summary

This summary is machine-generated.

Researchers developed a new method for controlling pH in Nuclear Magnetic Resonance (NMR) samples using light-activated photoacids. This technique allows precise, noninvasive pH adjustments within the NMR magnet, reducing sample handling and improving experimental reliability.

Keywords:

Buffer NMR Photo illumination Photoacid Protonation Titration

More Related Videos

Synthesis, Cellular Delivery and In vivo Application of Dendrimer-based pH Sensors

Synthesis, Cellular Delivery and In vivo Application of Dendrimer-based pH Sensors

Published on: September 10, 2013

Simultaneous pH Measurement in Endocytic and Cytosolic Compartments in Living Cells using Confocal Microscopy

Simultaneous pH Measurement in Endocytic and Cytosolic Compartments in Living Cells using Confocal Microscopy

Published on: April 28, 2014

Related Experiment Videos

Last Updated: May 21, 2025

Dissolution Dynamic Nuclear Polarization Instrumentation for Real-time Enzymatic Reaction Rate Measurements by NMR

Dissolution Dynamic Nuclear Polarization Instrumentation for Real-time Enzymatic Reaction Rate Measurements by NMR

Published on: February 23, 2016

Synthesis, Cellular Delivery and In vivo Application of Dendrimer-based pH Sensors

Synthesis, Cellular Delivery and In vivo Application of Dendrimer-based pH Sensors

Published on: September 10, 2013

Simultaneous pH Measurement in Endocytic and Cytosolic Compartments in Living Cells using Confocal Microscopy

Simultaneous pH Measurement in Endocytic and Cytosolic Compartments in Living Cells using Confocal Microscopy

Published on: April 28, 2014

Area of Science:

Chemistry
Biophysics
Analytical Chemistry

Background:

Proton exchange is crucial in chemical and biological systems.
Nuclear Magnetic Resonance (NMR) spectroscopy offers site-specific resolution for studying protonation events.
Traditional pH titration for NMR requires extensive sample handling and can lead to sample loss.

Purpose of the Study:

To introduce a novel, noninvasive method for controlling pH in NMR samples.
To demonstrate precise, in situ pH modulation using light-activated photoacids.
To reduce sample handling and improve the reliability of pH-dependent NMR studies.

Main Methods:

Utilized water-soluble photoacids to alter solution pH upon photoillumination.
Controlled pH by adjusting illumination wavelength and intensity.
Monitored in situ pH using internal standards with pH-sensitive chemical shifts.
Applied the method to protein samples with significant buffering capacity (>100 µM).

Main Results:

Achieved precise and calibrated pH control within the NMR magnet.
Demonstrated successful pH alteration from near neutral to acidic conditions.
Showcased the release of sufficient protons to induce meaningful pH changes in buffered samples.
Significantly reduced the need for extensive sample manipulation.

Conclusions:

Light-induced pH control offers a robust and reliable alternative for NMR experiments.
This novel approach enhances the efficiency and accuracy of pH-dependent NMR studies.
The method has broad applicability for investigating protonation events in various biological and chemical samples.