Bruker AVANCE 900 MHz NMR Spectrometer in the New NMR Building

As part of the Max T. Rogers NMR facility, the Bruker Avance 900 NMR spectrometer equipped with solution probes and solid-state NMR accessories was delivered on-site May 25, 2005 and has been installed. The TCI cryoprobe was delivered on September 9, 2006 and installed immediately after the delivery. The console accommodates five RF channels and tri-axis pulsed-field gradient accessories. The super-stabilized 900 MHz magnet (¹H frequency, field at 21.14 Tesla) is a super-conducting, persistent mode with a 5.4 cm bore, including a helium level sensor and magnetic stands. This master piece is the most powerful and sensitive machine ever in the market. It will play a very important role in both enhancing the structural biology research in academia and promoting the performance of chemical and pharmaceutical industries in the State of Michigan.

Our Bruker AVANCE^TM 900 MHz high performance digital NMR spectrometer is equipped with the following probeheads that are required for performing both sophisticated solution and solid-state NMR experiments.

TCI CryoProbe:

• The TCI triple-resonance inverse detection CryoProbe for ¹H observation (but the ¹³C coil and preamplifier are also cooled to support NMR experiments for ¹³C direct observation with high sensitivities) with ¹⁵N and ¹³C decoupling (5 mm sample diameter), ²H lock channel, Z-gradient coil for use with the GRASPTM accessory. It has improved signal/noise (S/N) ratios obtained by reducing the operating temperature down to about 20 k of both the coil and the pre-amplifier. As a result, the efficiency of the coil is improved and the noise temperature of the coil and the preamplifier is reduced. The dramatic increase in the S/N ratio by a factor of 3-4 for organic NMR samples, as compared to conventional probes, e.g. TXI, leads to a possible reduction in experiment time of up to 16 or a reduction in required sample concentration by a factor of up to 4.

Other solution NMR probes:

• Inverse triple-resonance (TXI) probe (5 mm sample diameter) for observation of ¹H while decoupling ¹³C and ¹⁵N, including ²H lockswitch for deuterium decoupling. Actively shielded X, Y, and Z-gradient coils for use with GRASPTM III accessory.

• Selective ¹³C observe probe with ¹H decoupling (10 mm sample diameter) capable of operating at +130 °C.

Solid-state NMR probes:

• Triple-resonance multinuclear VT CPMAS probe for triple-resonance experiments, such as REDOR and Double CP. 4 mm rotor design with 18 kHz maximum spinning speed. Single coil, triply tuned for ¹H, ¹³C and ¹⁵N crosspolarization, VT range -80 °C to +120 °C.

• E-Free Triple-resonance multinuclear VT CPMAS probe for triple-resonance experiments, such as REDOR and Double CP. E-Free configuration allows for minimal sample heating. 4 mm rotor design with 18 kHz maximum spinning speed. Single coil, triply tuned for ¹H, ¹³C and ¹⁵N crosspolarization, VT range -80 °C to +120 °C.

• Multinuclear VT CPMAS probe tuning from ¹³C to ¹⁵N, single coil, doubly tuned for 1H crosspolarization, 3.2 mm rotor design with 18 kHz maximum spinning speed, VT range -80 °C to +120 °C. The probe has been modified for tuning from ³¹P to ¹⁵N.

• Round coil E-Free CP probe configured for ¹H and ¹⁵N. Coil dimensions are for 5 mm tubes. E-Free configuration allows for minimal sample heating. The probe has an additional low-efficiency ³¹P channel, for the purpose of measuring sample alignment and integrity.

• Flat coil CP probe configured for ¹H and ¹⁵N. Coil dimensions are 7 mm width by 3 mm height and by 10 mm length. VT range from -120 °C to +150 °C. The probe has an additional low-efficiency ³¹P channel, for the purpose of measuring sample alignment and integrity.

Supporting instruments at the NMR facility

• Sample Prep Room (D122): There is an NMR sample preparation room in the new biomolecular NMR building. Basic instruments, including microcentrifuge, analytical balance, pH meter, hot plate/stirrer, pippettors, Mini Vortexer, glassware, plasticware, and chemicals are available for the NMR sample preparation. Users are required to bring their own NMR tubes, expensive solvents and buffers for their NMR sample preparations. High quality NMR tubes are strongly recommended. If a Shigemi micro cell is used, please choose the one with short (8 mm) and round bottom.

• Electronics Room (D124): There are some basic electronic devices available in the new NMR building. These include a Tektronix 1 GHz oscilloscope, a sweep generator, multimeters, and some other small parts and tools.

• Computer/Conference Room (D127): Linux workstations are available in computational rooms of both the Biochemistry building and the new biomolecular NMR building. These computers are served as off-line facility for NMR raw data archiving, data conversion and processing, data analysis, and structural calculation as well as inspection. Users are required to bring their own media (CD is preferred) to manipulate the data. These computers are also served as platforms for user training. In addition, wireless internet access is available at the facility.

Other Biomolecular NMR Instrument at MSU

A Varian Inova 600 MHz superconducting NMR spectrometer operating at 599.892 MHz (¹H frequency) interfaced with a Sun Microsystems Ultra2 UNIX station is located in the subbasement of the Chemistry Building as part of the Max T. Rogers NMR Facility. The console accommodates four RF channels and tri-axis pulsed-field gradient accessories. VT range is from 0 to +50 °C. The triple-resonance indirect probe pre-tuned for ¹H, ¹³C, and ¹⁵N and the Nalorac 5mm PFG switchable probe pre-tuned for ¹H, ¹³C are available.