Table 1.

Summary of the studied X-ray diffraction anomalies.

Anomaly	Visual description	Genesis	Possible actions
Background Ring	Blurry circular shadow centered around the primary beam position.	Scattering caused by partial ordering of the solvent molecules, or amorphous ice.	Diffraction images can be optimized to deal with this issue.
Diffuse Scattering	Blurry, gray smudges.	Caused by parts of the crystal not being well ordered.	Early detection allows for automated screening of different crystallization conditions.
Ice Ring	Thin, well-defined, concentric rings of varying strength.	Result when the crystal is not properly cryo-protected, stored, or shipped.	Indicates problems with vitrification. Early detection can be used for screening flash cooling conditions or automating annealing protocols.
Loop Scattering	Two or four small, arched shadows, located on opposite sides of the beam position.	Scattering caused by materials used to hold the crystal (loop).	In some cases, the quality of the data can be improved by increasing data redundancy.
Non-uniform Detector	Visible differences between the darkness of panels.	Inconsistent detectors making up the detector array cause uneven background shade.	Early detection of substantial non-uniformity allows for troubleshooting and proper planning before data collection.
Strong Background	Dark, full circle covering the center of the image.	The crystal’s suspension liquid absorbs and uniformly scatters X-rays.	Early detection allows for the modification of the data collection strategy, to compensate for the high background.
Artifact	Missing random (blocks) of pixels; black or white solid areas.	Data corruption, electronics failure, read/compression error.	Detection allows for early troubleshooting, detector repairs, and data collection planning.