HIGH-THROUGHPUT SOLUTION SCATTERING DATA COLLECTION SYSTEM

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 用于溶液X射线散射的自动化高通量数据收集系统的仪器的开发一直在继续，结合了石英毛细管流动池和Blu-Ice控制下的电动进样器。我们已经开发了一种真空毛细管池，它消除了两个窗口，并最大限度地减少背景散射水平。这使许多研究受益，其中低分子量或低浓度的大分子至关重要。真空飞行路径之外的第二个单元具有易于对准和维护的优点，适用于大多数溶液散射研究。两个流动池通过薄Tygon管连接到流体汉密尔顿540 B分配器和样品选择器，该分配器在Blu-Ice计算机控制下，该样品选择器将接受任何标准微孔板或几个PCR管条（最多总共8 × 12管）的冷冻铝块与三个电动微型线性平移台相结合，该微型线性平移台的垂直臂保持用于样品等分试样选择的注射器针头。典型的数据收集顺序包括1）在PCR管条上选择样品等分试样，2）通过Tygon管将等分试样转移到流动池，3）在石英毛细管内以约1微升每秒重复平移样品等分试样，紧接着开始一系列散射数据采集，4）将样品回收到PCR管，5）清洁毛细管和Tygon管。自动化序列消除了手动样品更换，并导致更有效地使用射束时间。 未来的目标包括提高样品加载的可靠性，包括消除气泡的形成。

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. The development of instrumentation for an automated high throughput data collection system for solution x-ray scattering has been continued, combining a quartz capillary flow cell and a motorized sample changer under Blu-Ice control. We have developed an in-vacuum capillary cell, which eliminates two windows and minimizes background scattering level. This has benefitted a number of studies in which macromolecules of low molecular weight or at low concentrations are critical. A second cell, outside the vacuum flight path, has the advantage of ease of alignment and maintenance for the majority of solution scattering studies. Both flow cell are connected via thin Tygon tubing to a fluid Hamilton 540B dispenser, which is under Blu-Ice computer control, and a sample selector, which combines a refrigerated aluminum block accepting any of the standard micro-plates or several PCR tube strips (up to total 8x12 tubes), with three motorized miniature linear translation stages whose vertical arm holds a syringe needle for sample aliquot selection. A typical data collection sequence involves 1) selection of a sample aliquot on PCR tube strips, 2) transfer of the aliquot to the flow cell via a Tygon tube, 3) repetitive translation of sample aliquot within the quartz capillary at around 1 microliter per second, immediately followed by the initiation of a series of scattering data acquisition, 4) sample recovery to a PCR tube, 5) cleaning of the capillary and Tygon tubing. The automated sequence eliminates manual sample change, and has led to more efficient use of beam time. Future goals include improved reliability of sample loading, including the elimination of bubble formation.