Solid State NMR (SSNMR)

NMRFAM is greatly expanding its solid-state NMR capabilities in 2020, with five spectrometers being installed and upgraded with consoles, amplifiers and magic-angle spinning (MAS) probes. Capabilities already or will soon include ¹³C-detection at moderate (up to 25 kHz) MAS rates, ¹H-detection at MAS rates up to 60 kHz, REDOR (including ³¹P and ¹⁹F), and oriented sample (PISEMA) experiments. Staff are available to support collection of multidimensional data sets at fields ranging from 600 to 900 MHz, as well as support for data analysis and interpretation. NMRFAM is also adding substantial capabilities to study broadband nuclei including quadrupolar nuclei, in support or applications to chemistry, materials science and engineering. Please stay tuned to the NMRFAM SSNMR page for updates as instruments come fully online.

Biological SSNMR

Solid state NMR (SSNMR) spectroscopy is used for studying wide range of biomolecular systems such as crystalline proteins, fibrillar proteins, membrane proteins, as well as concentrated soluble and sedimented protein samples. For SSNMR analysis, isotopically labeled (13C and 15N) protein samples are centrifugated to obtain hydrated pellets that are packed into MAS (magic angle spinning) rotors. The sample in the rotor is spun at magic angle axis, i.e., 54.7o with respect to Bo field (z-axis). The maximum spinning frequency is inversely proportional to the probe rotor diameter, and therefore requires distinct MAS probe for achieving different range of spinning speeds. Protein structural data is obtained by using 13C and/or 1H detected experiments. For 13C detected experiments, typical MAS rotor diameter sizes are 1.6 mm and 3.2 mm with respective sample volumes, 10 and 25 µl. Under these conditions 13C detected experiments are acquired with MAS rates of 10 to 35 kHz. On the other hand, 1H-detected experiments require ultrafast and very fast MAS probes with smaller rotor diameters, such as 1.3 mm and 0.7 mm with respective samples volumes, 3 and 1 µl, and MAS rates of 60 to 100 kHz are used. For 1H-diluted or perdeuterated protein samples, 1H detected experiments are acquired using fast MAS (1.6 mm) or ultrafast (1.3 mm) MAS probes using MAS rates of 30 to 60 kHz.