BER Structural Biology and Imaging Resources
Synchrotron, Neutron, and Cryo-EM
U.S. Department of Energy | Office of Science | Office of Biological and Environmental Research

Small-Angle Neutron Scattering

Nanoscale structure of biomolecules and biomaterials

New insight into overcoming plant recalcitrance. Small-angle neutron scattering and supercomputing reveal a pathway to significantly improve the production of renewable biofuels and bioproducts. An organic solvent (yellow) and water (blue) will eventually separate and form nanoclusters on the hydrophobic and hydrophilic sections of plant material (green), driving the efficient deconstruction of biomass. [Courtesy Oak Ridge National Laboratory]

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

  • Envelope structure and scattering properties of Bacillus subtilis. SANS reveals the structure and composition of the cell envelope of a living B. subtilis cell. From top to bottom: orange S-layer proteins cover the cell wall (brown), blue lipids largely comprise the cell membrane, and the underlying cytoplasm contains proteins (orange) and nucleic acids (shades of green). [From 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]. Reused under a Creative Commons license (CC BY 4.0).]

    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
  • Bio-membranes
  • Complex systems (e.g., in cellulo experiments, viruses)
  • Biomass and biofuels
  • Biomimetic and bioinspired systems
  • Soils

See more examples in Science Highlights

Sample Considerations

  • 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.


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.