Related Experiment Video
Updated: Mar 1, 2026
07:33
Quantifying Mixing using Magnetic Resonance Imaging
Published on: January 25, 2012
11.4K
Optimized fast mixing device for real-time NMR applications.
Rémi Franco1, Adrien Favier1, Paul Schanda1
1Institut de Biologie Structurale, Université Grenoble Alpes, CEA, CNRS, 71 avenue des Martyrs, 38044 Grenoble Cedex 9, France.
Summary
This study introduces a novel, inexpensive fast mixing device for real-time Nuclear Magnetic Resonance (NMR) spectroscopy. The device enhances magnetic field homogeneity, aiding studies of molecular kinetics and protein folding intermediates.
Area of Science:
- Biophysical Chemistry
- Analytical Chemistry
- Spectroscopy
Background:
- Fast mixing is crucial for studying molecular kinetics using real-time Nuclear Magnetic Resonance (NMR) spectroscopy.
- Previous methods faced limitations in magnetic field homogeneity due to the injector remaining in the detection volume.
Purpose of the Study:
- To present an improved fast mixing device for off-equilibrium studies.
- To enhance magnetic field homogeneity in NMR experiments.
- To facilitate the study of molecular kinetics and protein folding.
Main Methods:
- Development of a novel fast mixing device for rapid solution mixing within an NMR probe.
- Incorporation of a mechanism to remove the injector from the NMR detection volume post-mixing.
- Demonstration of the device's performance on liquid-state NMR spectrometers without hardware modification.
Main Results:
- The improved device ensures good magnetic field homogeneity, independent of the initial sample volume.
- The apparatus is simple, inexpensive, and compatible with various liquid-state NMR spectrometers.
- Successful application in studying protein folding and characterizing transient folding intermediates.
Conclusions:
- The developed fast mixing device offers a significant improvement for real-time NMR spectroscopy.
- It enables high-quality off-equilibrium kinetic studies and structural characterization of transient species.
- The device's simplicity and versatility make it broadly applicable in NMR research.
Related Concept Videos
01:12Double Resonance Techniques: Overview
820
Double resonance techniques in Nuclear Magnetic Resonance (NMR) spectroscopy involve the simultaneous application of two different frequencies or radiofrequency pulses to manipulate and observe two distinct nuclear spins. One important application of double resonance is spin decoupling, which selectively suppresses coupling with one type of nucleus while observing the NMR signal from another nucleus, simplifying the spectrum and enhancing resolution.
Spin decoupling is usually achieved by...
Spin decoupling is usually achieved by...
820
01:20NMR Spectrometers: Overview
2.3K
NMR spectrometers consist of a strong magnet, a radiofrequency transmitter, and a detector attached to a computer console for recording spectra of samples containing NMR-active nuclei. In first-generation NMR instruments called continuous-wave spectrometers, the resonance frequencies of the nuclei are determined by frequency-sweep or field-sweep methods. The magnetic field strength is fixed and the rf signal is swept in the former, while the radiofrequency signal is fixed and the magnetic field...
2.3K
01:17NMR Spectrometers: Radiofrequency Pulses and Pulse Sequences
1.9K
A pulse is a short burst of radio waves distributed over a range of frequencies that simultaneously excites all the nuclei in the sample. Upon passing a radio frequency pulse along the x-axis, the nuclei absorb energy corresponding to their Larmor frequencies and achieve resonance. This shifts the net magnetization vector from the z-axis toward the transverse plane. This angle of rotation of the magnetization vector, or the flip angle, is proportional to the duration and intensity of the pulse.
1.9K
01:14NMR Spectrometers: Resolution and Error Correction
1.1K
When magnetic nuclei in a sample achieve resonance and undergo relaxation, the signal detected in NMR is an approximately exponential free induction decay. Fourier transform of an exponential decay yields a Lorentzian peak in the frequency domain. Lorentzian peaks in an NMR spectrum are defined by their amplitude, full width at half maximum, and position, where the peak width is governed by the spin-spin relaxation time alone. In real experiments, however, the applied magnetic field is rendered...
1.1K
00:52¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
1.3K
At room temperature, the chair conformer of cyclohexane undergoes rapid ring flipping between two equivalent chair conformers at a rate of approximately 105 times per second. These two chair conformers are in equilibrium. The rapid ring flipping results in the interconversion of the axial proton to an equatorial proton and an equatorial to the axial proton. Such interconversions are too rapid and cannot be detected on the NMR timescale. Hence, the NMR spectrometer cannot distinguish between the...
1.3K
01:162D NMR: Overview of Homonuclear Correlation Techniques
723
Homonuclear correlation spectroscopy (COSY) is a powerful technique used in Nuclear Magnetic Resonance (NMR) spectroscopy to study the correlations between nuclei of the same type within a molecule. It provides information about scalar couplings between adjacent nuclei, which helps determine connectivity and structural information. There are several COSY variants, each with its unique strengths and experimental parameters.
COSY90 is the standard two-dimensional (2D) COSY experiment that...
COSY90 is the standard two-dimensional (2D) COSY experiment that...
723