PLASTIC PIPETTE TIPS AS SAMPLE MOUNTS FOR PROTEIN CRYSTALLOGRAPHY X-RAY DIFFRACT

这个子项目是众多研究子项目之一

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Mounting samples for crystal quality screening and data collection can often be problematic. Manual manipulation of the crystal is traditionally required to place it properly inside a mount. Crystals are commonly damaged both by physical contact and exposure to air. To streamline high-throughput crystallization facilities and automated x-ray diffraction data collection, the capette, a new sample container compatible with the SAM system was developed at SSRL in collaboration with the Hauptmann Woodward Institute. The capette will be used for both crystal growth and x-ray diffraction experiments at cryogenic and room temperature, mitigating direct sample manipulation. The capette will be used as a pipette tip with both manual pipetters and automated liquid handling robots enabling solutions for crystal growth to be easily drawn inside. For x-ray data collection, the larger end of the cappette fits onto a metal base and the assembly fits inside the SSRL cassette or uni-puck sample storage container. When used for x-ray data collection, the capette produces a low x-ray background so complete data sets may be collected from samples within the capette. Based on materials testing and selection from previous years, arrangements were initiated with a company to produce a capette with a much thinner wall at the smaller diameter portion which holds the samples used for data collection. This new capette will be produced by fusing a very thin walled small diameter extruded tube to a larger diameter injection molded base. Beam time was used this year to test which of the thin walled tubing supplied by this company had the best properties for data collection. It was found that capettes should be 200 microns in diameter or smaller to facilitate sample centering in the x-ray beam and proper cryo-cooling.