Small-Angle Neutron Scattering
Nanoscale structure of biomolecules and biomaterials
Like small-angle X-ray scattering (SAXS; solution X-ray scattering), small-angle neutron scattering (SANS) is used to study ensemble structures of biological materials of any morphology over a wide range of length scales. SANS, however, can take advantage of the very different neutron scattering cross-sections of hydrogen and deuterium (D), making it possible to selectively highlight different components within a complex system. In combination with H2O/D2O contrast variation and D-labeling techniques, SANS provides unique information about complexes of biomolecules and hierarchical structures (~1–500 nm) in solution or in situ. Ultra-SANS extends the accessible length scales to several microns. Time-resolved SANS experiments can also be conducted for kinetic studies, with timescales typically longer than for SAXS (seconds to minutes).
Key Features of SANS
- Probes a wide range of length scales (~1 to 500 nm)
- Penetrates and is non-destructive to samples, causing no radiation damage
- Leverages exquisite sensitivity to hydrogen isotopes
- Detects specific details in complex systems using targeted isotope contrast
BER Researchers Use SANS to Study:
- Biomacromolecules and their assemblies
- Complex systems (e.g., in cellulo experiments, viruses)
- Biomass and biofuels
- Biomimetic and bioinspired systems
See more examples in Science Highlights
- SANS measurements require no special sample preparation.
- SANS beamlines are equipped with a wide variety of sample environments that can be used to measure liquids, solids, suspensions, etc.
- For liquids (e.g., proteins in solution) or suspensions, around 300 microliters of sample are needed for each measurement.
- Immersing or dissolving samples in different concentrations of D2O can vary the contrast of the sample.
SANS Beamlines at DOE User Facilities
Each beamline has unique characteristics. To determine the user facility and beamline best suited to your science questions, see additional information and beamline contacts at the links below.
- Biological Small-Angle Neutron Scattering Instrument (Bio-SANS) — High Flux Isotope Reactor
- General-Purpose Small-Angle Neutron Scattering Diffractometer (GP-SANS) — High Flux Isotope Reactor
- Extended Q-Range Small-Angle Neutron Scattering Diffractometer (EQ-SANS) — Spallation Neutron Source
- Ultra-Small-Angle Neutron Scattering Instrument (USANS) — Spallation Neutron Source
Nickels, J. D., et al. 2017. “The in vivo structure of biological membranes and evidence for lipid domains,” PLOS Biology 15(5), e2002214. DOI: 10.1371/journal.pbio.2002214.
Pingali, S.V., et al. 2020. “Deconstruction of biomass enabled by local demixing of cosolvents at cellulose and lignin surfaces,” PNAS 117(29), 16776-81. DOI: 10.1073/pnas.1922883117.