Automated, Simultaneous Small- And Wide-Angle X-Ray Scattering From Protein Solutions

We describe the instrumentation for protein solution X-ray scattering at beamline X9 of the National Synchrotron Light Source. By utilizing two detectors, we collect scattering data within a continuous q-range of ∼0.005-2.0Å−1. The scattering data from the two detectors are merged and processed using a set of Python scripts. The vacuum-compatible sample cell features flat windows that produce minimal scattering background. The concentration of the protein sample is quantified by measuring the UV-Vis absorption spectrum near the X-ray beam spot. Samples stored in 0.6ml micro-centrifuge tubes can be measured in groups of 15 automatically. The instrument can also be used together with a size exclusion chromatography to measure freshly purified protein samples.