Data Analysis

James R. Thompson, Ph.D., core director, and Donnie Berkholz, research fellow, discussing the structural features of an amyloid-forming protein.

Using 3-D vision with stereo glasses, James R. Thompson, Ph.D., core director (left), and Donnie Berkholz, Ph.D., research fellow, discuss structural features of an amyloid-forming protein that models the blue electron density map shown.

Once data are collected, they must be processed and analyzed. A variety of software is available in the X-ray Crystallography Core for this purpose.

Data analysis, which results in the production of an electron density map, includes finding and indexing reflections, refining the unit cell, and determining the space group. This process can be completed in as few as several days, but may take much longer if new analysis methods must be developed to solve difficult data sets.

After an electron density map is produced, there are additional steps in the analysis process, such as phase determination, and model building and refinement.

Sometimes, new data sets must be collected from higher quality crystals — or from crystals of other similar molecules — before any chemical coordinate models can be built and refined against the diffraction data and electron density maps. The X-ray Crystallography Core guides users through these steps.