Beamline B21: high-throughput small-angle X-ray scattering at Diamond Light Source.

Area of Science:

• Structural Biology
• Biophysics
• Materials Science

Background:

• Small-angle X-ray scattering (SAXS) is a powerful technique for characterizing the size and shape of macromolecules in solution.
• Synchrotron-based SAXS facilities offer high flux and tunable energy, enabling detailed structural investigations.
• Automated sample handling and advanced detectors are crucial for high-throughput structural biology studies.

Purpose of the Study:

• To describe the capabilities and performance of the B21 SAXS beamline at Diamond Light Source.
• To highlight the automated sample loading and analysis features for biological macromolecules.
• To showcase the suitability of the beamline for a wide range of sample types, including viscous and solid materials.

Main Methods:

• The B21 beamline utilizes a 3 GeV storage ring with a bending magnet source.
• A double multi-layer monochromator and toroidal focusing optic deliver a high photon flux to the sample.
• An in-vacuum Eiger 4M detector records scattering data, coupled with automated liquid chromatography and robotic sample loading.

Main Results:

• The beamline delivers 2 x 10^12 photons/second to a 34 x 40 µm focal spot.
• Automated sample loading allows for high-throughput analysis of solution samples.
• The beamline covers a scattering vector range of 0.0026 to 0.34 Å⁻¹ with low background.

Conclusions:

• The B21 beamline is a versatile and highly automated SAXS facility optimized for biological macromolecules.
• Its capabilities facilitate efficient structural characterization of diverse sample types.
• The beamline has been operational since 2013, supporting a full user program.