STOPPED FLOW TIME RESOLVED SAXS DEVELOPMENT

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。 时间分辨SAXS是BioCAT提案中的核心项目之一。发展停流时间分辨SAXS实验使用标准蛋白质(细胞色素c)和RNA样品。结果表明，BioCAT能够以4ms的时间分辨率和1.8ms的反应停滞时间，采用SFM-400停流仪(Bio-Logic)与Aviex CCD相结合的条纹摄像模式进行时间分辨SAXS实验。对于样品与试剂的每一次混合事件，在一次数据采集中可以在Aviex CCD芯片上记录16个连续条纹帧，从而能够在总时间窗口毫秒内进行数据采集。可以通过使用更大的每条条纹的曝光时间来实现更长的时间窗口。样品消耗量可维持在每次混合事件约40微升的低水平。当RNA和蛋白质样本的浓度分别低至~1 mg/ml和5 mg/ml时，可以通过平均20个数据集的结果来产生高质量的数据。实验结果已经在英国BSR2007会议上发布了一张海报，为这项技术做广告。在Run 2007-3中，我们测试了从APS探测器池借来的Pilatus 100K探测器，并与Aviex进行了比较。对于200赫兹或更低的成帧速率，用Pilatus检测器获得的数据质量比用Aviex检测器获得的数据质量要好得多。

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. Time resolved SAXS is one of the core projects in the BioCAT proposal. Development stopped flow time-resolved SAXS experiments used standard protein (cytochrome c) and RNA samples. The results demonstrate that BioCAT is capable of performing time-resolved SAXS experiments by using the SFM-400 stopped-flow instrument (Bio-Logic) combined with the Aviex CCD in streak camera mode at a time resolution of 4 ms with a reaction dead time of 1.8 ms. For each single mixing event of a sample with a reagent, 16 continuous streak frames can be recorded on the Aviex CCD chip in a single data acquisition, enabling data acquisition over a total time window of 64 ms. Longer time windows may be achieved by using larger exposure times per streak. Sample consumption can be maintained at a low level of ~ 40 ul per mixing event. RNA and protein samples at concentrations as low as ~ 1mg/ml and 5 mg/ml respectively can yield high quality data by averaging the results of 20 data sets. The results of the experiments have been presented in a poster to advertise this technique in the BSR2007 conference in England. In run 2007-3 we tested a Pilatus 100K detector borrowed from the APS detector pool in comparison to the Aviex. The data quality obtained with the Pilatus detector is considerably superior to that obtained with the Aviex detector for framing rates of 200 Hz or slower.