In situ screening and data collection using the XtalCheck system

Protein crystallography often requires screening large numbers of crystals to identify samples that are suitable for X-ray diffraction experiments. Specifically, crystallographers usually loop and cryofreeze samples for X-ray screening to identify whether the sample contains a protein or salt and to evaluate diffraction resolution, mosaicity and other crystal parameters. This iterative process of mounting and screen ing of many samples is time consuming and rarely automated.

The XtalCheck system addresses this bottleneck by automating diffraction data collection for crystals directly from SBS forma t crystallization plates. With the XtalCheck system, one can quickly and easily survey many crystallization experiments by eliminating the need to harvest and cryo-protect samples. Moreover, one can perform serial crystallography experiments, by collecting data from multiple crystals, to achieve complete data sets that can be used for structure solution. The system also includes automated imaging of crystallization dro ps with a queuing system that was developed to use in laboratories with an existing X-ray diffraction system.