Spatially resolved anomalous dispersion (SpReAD) refinement is a method to analyse the oxidation states of individual protein-bound metals and is based on collecting several x-ray diffraction datasets across an x-ray absorption edge. Such an approach can expose crystals to relatively high total dose of radiation. This can result in radiation damage, including reduction of metals.
Here, we have conducted experiments for SpReAD analysis on HZB MX beamline 14.1. To analyse the effect of dose on the result of the experiments, we have tested different transmission settings to vary the total dose per experiment and test whether data collected at low transmission are suitable for SpReAD refinement.