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

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 对由六种不同透明等级的聚合物生产的相同尺寸的塑料毛细管进行了测试，以确定哪种聚合物产生的X射线背景最小，最适合生产用于低温下蛋白质结晶学X射线衍射数据收集的样品容器。被测试的聚合物是：丙烯腈-丁二烯-苯乙烯(ABS)、聚甲基丙烯酸甲酯(丙烯酸酯)、聚酰胺(PA)、高抗冲聚苯乙烯(HIP)、聚碳酸酯(PC)和低密度聚乙烯(LPDE)。数据收集在SSRL BL7-1上。每个样品在100K的温度下暴露在0.976埃X射线下约30秒。监测入射强度，并改变曝光时间，以确保每个样品获得相同的X射线剂量。注意从每个测试样本中暴露出相同体积的塑料。在曝光过程中，每个塑料都被旋转了5度。散射强度由Q315 CCD探测器测量，距离样品251 mm，最大分辨率为1.37A。还评估了每个塑料容器的光学性能。这项工作是与豪普特曼·伍德沃德医学研究所的研究人员合作完成的，目标是开发一种既可用于晶体生长又可用于X射线衍射质量筛选的小型塑料毛细管。毛细管将被用作吸管尖端，带有手动移液器和自动液体处理机器人，使晶体生长的解决方案能够轻松地提取到内部。对于X射线数据采集，毛细管的较大端安装在金属底座上，组件安装在SSRL盒或单圆盘样品存储容器内，并与SSRL自动样品安装系统兼容，用于自动筛查和远程访问数据收集。

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. Plastic capillaries of identical size produced from six different clear grades of polymers were tested to determine which polymer produces the smallest x-ray background and is the most suitable for the production of sample containers used for protein crystallography x-ray diffraction data collection at cryogenic temperatures. The polymers tested were: Acrylonitrile butadiene styrene (ABS), Polymethyl methacrylate (Acrylic), Polyamide (PA), High Impact Polystyrene (HIP), Polycarbonate (PC), and Low Density Polyethylene (LPDE). Data were collected on SSRL BL7-1. Each sample was exposed to 0.976 A x-rays for about 30 seconds at a temperature of 100 K. The incident intensity was monitored and the exposure time varied to ensure each sample received an equivalent x-ray dose. Care was taken to expose the same volume of plastic from each sample tested. Each plastic was rotated five degrees during the exposure. The scattered intensity was measured by a Q315 CCD detector located at a distance of 251 mm from the sample giving a maximum resolution of 1.37 A. The optical properties of each of the plastic containers were also assessed. This work was done in collaboration with researchers at the Hauptman Woodward Medical Research Institute with the goal of developing a small plastic capillary that can be used both for crystal growth and x-ray diffraction quality screening. The capillary 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 capillaries fits onto a metal base and the assembly fits inside the SSRL cassette or uni-puck sample storage container and is compatible with the SSRL automated sample mounting system for automated screening and remote access data collection.