What is NMR Spectroscopy?

Nuclear magnetic resonance (NMR) spectroscopy is a research technique that exploits the magnetic properties of certain atomic nuclei. It determines the physical and chemical properties of atoms or the molecules in which they are contained. It relies on the phenomenon of nuclear magnetic resonance and can provide detailed information about the structure, dynamics, reaction state, and chemical environment of molecules. The intramolecular magnetic field around an atom in a molecule changes the resonance frequency, thus giving access to details of the electronic structure of a molecule.

Most frequently, NMR spectroscopy is used by chemists and biochemists to investigate the properties of organic molecules, although it is applicable to any kind of sample that contains nuclei possessing spin. Suitable samples range from small compounds analyzed with 1-dimensional proton or carbon-13 NMR spectroscopy to large proteins or nucleic acids using 3 or 4-dimensional techniques. The impact of NMR spectroscopy on the sciences has been substantial because of the range of information and the diversity of samples, including solutions and solids.

Our Mission

We are a Biomedical Technology Research Center (BTRC) focused on the development of new technology for NMR spectroscopy and to make it available to the biomedical research community for structure determination of proteins in biological supramolecular assemblies, such as membrane proteins or virus particles.

Core Research Projects

The BTRC has four core Technological Research and Development components:

Develop molecular biology, isotopic labeling and refolding of membrane proteins in phospholipid bilayers.

Design and construct probes for solid-state NMR of lossy samples.

Develop and implement new solid-state NMR experiments.

Develop methods to calculate protein structures from solid-state NMR experimental data.

Our Facilities

The NMR 'Bubble'

The ‘Bubble’ is the air-supported structure that houses the instrumentation of the Resource. The building meets the demanding requirements of high-field NMR magnets. It has a very high ceiling and has no steel-containing beams, pillars, or columns so as to not interfere with the homogeneity of the magnets or the placement of the equipment. The insulated double skin design ensures excellent temperature regulation.

The purpose of the facility is to create high-resolution images of proteins that represent their shape and arrangement, atom-by-atom. It’s critical information with a direct link to human health.

Each NMR spectrometer houses a superconducting magnet, chilled with liquid helium to temperatures approaching absolute zero. Vials of purified protein, embedded in double-layer membranes just as they would be in cells, fit into custom-designed instruments inserted into the core of the magnet.

Within the strong magnetic field, radio frequency pulses perturb the atoms that make up the protein. How each atom responds depends on their proximity to adjacent atoms.

The Wet-Lab

To obtain proteins for structure determination it is important to have the opportunity to produce recombinant proteins as efficiently as possible. For this purpose recently many molecular biology techniques have been introduced in the wet-lab allowing both the production and purification of novel proteins as well as the production of mutants of these proteins. Additionally, various bioassays can be implemented in the lab such as protein-protein and protein-DNA interaction assays. The molecular biological and biochemical experiments will provide additional opportunities to answer questions concerning both structure and function of the studied proteins.

Our team maintains a well equipped wet-lab permitting most biochemical and molecular biology experiments to be performed. Normal laboratory facilities such as, pH electrodes, centrifuges, water baths, balances, a sonificator, a speedvac, various gel-electrophoresis systems, a gel imaging system and a stereo-equipment are available, as well as equipment for most biochemical and molecular biological experiments, such as sequencing, protein-protein and protein-DNA interactions. The laboratory permits us to produce and purify the proteins required for structure determination by NMR.

The Electronics Shop

This work area is equipped with several test instruments, including a Hewlett Packard 8752A 300 kHz – 1.3 GHz Network Analyzer and a Hewlett Packard 4815A 0.5 – 108 MHz Vector Impedance Meter. The electronics shop shares one of four oscilloscopes with the spectrometers including, Tektronics models TDS 5104 (1 GHz), TDS 782A (1 GHz), TDS 3052B (500 MHz) and One Agilent scope model H-P54835A. A Tektronics 2712 9 kHz – 1.8 GHz spectrum analyzer is also available. For construction and prototype development, the shop is equipped with a Microlux Mini Mill and Mini Lathe as well as a Craftsman table top drill press.

In addition to commercial probes, our facility includes numerous home-built probes, both for static aligned-sample NMR and for Magic Angle Spinning NMR. This enables us to tailor our instrumentation to satisfy the unique, specialized requirements of our collaborators. The probe body and parts are designed in house and commissioned to the UCSD machine shop or to external vendors. NMR probes are then assembled and tested in-house. 


  • All spectrometers in the Bubble are dedicated to solid-state NMR
  • The most frequently used probes are listed below. 
  • Specialty probes are available or built upon demand for collaborative and service projects, e.g. 17O, 2H . 
  • Most samples are run at temperatures between -20oC and +60oC, however the sample temperature depends on the specific probe, system and MAS spinning speed





900 MHz

Bruker Avance III HD

  • 3.2 mm H/C/N MAS Bruker E-free <20 kHz

  • 1.3 mm H/C/N MAS Bruker <65 kHz

  • HN 3mm, 5 mm  Static Home-Built (Loop-Gap Resonator Coil)

750 MHz

Bruker Avance III HD

  • 3.2 mm H/C/N MAS Bruker E-free <20 kHz

  • 4 mm H/C/N MAS Bruker <20 kHz

700 MHz

Bruker Avance II

  • 3.2 mm H/C/N MAS home-built <20 kHz (Agilent/Revolution rotors)

  • HNC, HN 5 mm static home-built (strip-shield coil)

  • HDN 3mm Static Home-Built (Triple-Tuned Solenoid Coil)

700 MHz

Bruker Avance

  • 3.2 mm H/C/N MAS home-built <20 kHz (Agilent/Revolution rotors)

  • HNC, HN 5 mm static home-built (strip-shield coil, MAGC, flat coil)

  • HP 5 mm scroll coil home built static probe

500 MHz

Varian Inova

  • HNC, HN 5 mm static home-built

  • HP 5 mm scroll coil home built static probe

Start typing and press Enter to search