DATASW, a tool for HPLC-SAXS data analysis.

Small-angle X-ray scattering (SAXS) in solution is a common low-resolution method which can efficiently complement the high-resolution information obtained by crystallography or NMR. Sample monodispersity is key to reliable SAXS data interpretation and model building. Beamline setups with inline high-performance liquid chromatography (HPLC) are particularly useful for accurate profiling of heterogeneous samples. The program DATASW performs averaging of individual data frames from HPLC-SAXS experiments using a sliding window of a user-specified size, calculates overall parameters [I(0), Rg, Dmax and molecular weight] and predicts the folding state (folded/unfolded) of the sample. Applications of DATASW are illustrated for several proteins with various oligomerization behaviours recorded on different beamlines. DATASW binaries for major operating systems can be downloaded from http://datasw.sourceforge.net/.