banner-efree.jpg

RF Heating Reduction with Uncompromised NMR Performance

Efree Probes for both Static and Rotating Solids

RF sample heating results from the interaction between the electric field and the sample. In the case of wet and salty samples (such as for biological samples) the use of high amplitude proton decoupling can lead to excessive sample heating. This situation can be alleviated by reducing the E-field at the location of the sample. A low inductance proton RF coil can achieve this.

Minimizing RF Heating

Bruker’s Efree probes employ the combination of a low inductance proton coil with a high efficiency solenoid for observe frequencies, yielding a probe with:

  • Minimal RF Heating
  • Uncompromised RF performance on proton
  • Uncompromised performance on observe channels
  • Excellent B1-homogeneity on all channels
  • Outstanding tuning stability

Built for your Applications

Efree probes are available for static as well as MAS applications. Crystalline proteins achieve a very high resolution in magic angle spinning probes while proteins aligned in bicelles or oriented membranes are measured in the static probes.

Efree Probes for Biological Solid State NMR

  • Available from 500 to 950 MHz
  • In double and triple resonance configurations
  • MAS probes:

    • 4 mm or 3.2 mm
    • Automatic sample eject

  • Static probes:

    • Flat coil (for samples oriented on glass plates) or
    • Solenoid (for samples oriented in bicelles)

Efree RF Architecture

  • Balanced RF design
  • Based on Dual Coil design

  • Low Inductance RF Coil strongly minimizes RF heating

  • High RF efficiency

  • High Sensitivity (X/Y)

  • High 1H fields (but higher RF power required)

  • Used in MAS and Static probes

  • Best for salty/wet samples

Progressive Pitch™

  • optimized geometry of RF coil
  • increased B1-homogeneous region (~+35%)
  • increased S/N

Used in:

  • TL2 and Efree probes
  • MAS and Static

Efree MAS Probes

Features

  • Available for 500-950 MHz
  • Triple Resonance
  • 4.0mm/ 3.2 mm/(2.5 mm)
  • Top Eject
  • Frequency Options:
    - H/C/N
    - H/C/D
    - H/../..

Applications

  • Solid Peptide & Proteins
  • Typically wet/salty samples
  • Optimized to avoid RF heating

Requirements

  • 300W 1H /500W X /500W Y
  • HP Pre-amps

Accessories

  • Rotors, Caps
  • (Disposable) Inserts
  • MAS eject tube
  • BCU-X down to -60oC

Efree Static Probes

Features

  • Available for 500-950 MHz
  • Double/Triple Resonance
  • 7 x 5.5 or 7 x 3 mm flat coil
  • 5 mm solenoid
  • 31P to check alignment
  • Frequency Options:
    - H/N
    - H/C/N
    - H/C/D
    - H/F/C
    - H/../.. 

Applications

  • Aligned Crystals
  • Proteins aligned on glass plates
    - ‘flat’-coil
  • Proteins in Bicelles
    - solenoid

Requirements

  • 300W 1H /500W X / 500W Y
  • HP Pre-amps

Accessories

  • Sample Cells
  • BCU-X down to -60oC

Experiments Performed with Efree Probes

Dedicated High-End Technologies for BioSolids and Materials

700 MHz HCN CPMAS

apps-efree1.png
GB1 project on Efree 4 mm 700 MHz HCN CPMAS probe. Experiments performed at and above room temperature. Resolution as found through isoleucine resonances better than 15 Hz. Sample courtesy of Vladimir Ladhizansky (U. Guelph).
700 MHz HCN CPMAS
GB1 project on Efree 4 mm 700 MHz HCN CPMAS probe. Experiments performed at and above room temperature. Resolution as found through isoleucine resonances better than 15 Hz. Sample courtesy of Vladimir Ladhizansky (U. Guelph).

A Large numbers of proteins are not amenable to X-ray crystallography or liquid state NMR because:

  • Especially membrane proteins

  • Solubility poor or impossible

  • Crystallization impossible or insufficient for X-ray

700 MHz HCN CPMAS

apps-efree3.png
GB1 project on Efree 4 mm 700 MHz HCN CPMAS probe. Experiments performed at and above room temperature. Resolution as found through isoleucine resonances better than 15 Hz. Sample courtesy of Vladimir Ladhizansky (U. Guelph).
700 MHz HCN CPMAS
GB1 project on Efree 4 mm 700 MHz HCN CPMAS probe. Experiments performed at and above room temperature. Resolution as found through isoleucine resonances better than 15 Hz. Sample courtesy of Vladimir Ladhizansky (U. Guelph).

There is a rapid method development by increasing number of groups to adapt solution strategies to solids. In parallel the increased customer interest has led to a wide range of well-established methods and pulse programs  available via the Bruker BioSpin pulse program library. This allows allowing novice researcher to enter the field of biological solid state NMR.

Static

apps-efree-stat1.png
750 MHz Efree SAMMY spectrum of 2 mM <sup>15</sup>N-uniformly labeled Vpu in 14-O-PC/6-O-PC bicelles. Spectrum courtesy of S. Opella, UCSD.
Static
700 MHz Efree PISEMA spectrum of KdpF: 30 residue protein from the Mycobacterium tuberculosis genome, in oriented membranes. Sample courtesy of T. Cross NHMFL.

LabScape

Service & Life Cycle Support for Magnetic Resonance and Preclinical Imaging

Bruker’s commitment to provide customers with unparalleled help throughout the buying cycle, from initial inquiry to evaluation, installation, and the lifetime of the instrument is now characterized by the LabScape service concept.

LabScape Maintenance Agreements, On-Site On-Demand and Enhance Your Lab are designed to offer a new approach to maintenance and service for the modern laboratory

Download LabScape Brochure