EVALUATING DYNAMIC RANGE AND PEAK CAPACITY IN MASS SPECTROMETRY EXPERIMENTS

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。 质谱学实验的价值通常由结果的数量和质量来评估，特别是在 蛋白质组学实验，其中获得的信息(即蛋白质鉴定)通常被移除两个或两个以上步骤 从从中得出它的原始数据。然而，分析的质量可以在冗长的 获得该标识所需的后处理步骤(例如，SEQUEST处理)，方法是检查RAW的属性 数据。质谱学实验质量的关键但很少被评估的措施包括 数据质量，如动态范围、峰值容量和检测到的感兴趣信号的数量。我们正在开发 为我们质谱仪上生成的每个数据集全局评估这些数量的软件。该软件需要 MS1和MS2格式的质谱学数据文件作为输入并且：(1)对检测到的信号的数量进行计数， 其中，“信号”被定义为在用户内的连续大规模扫描中发现并持续存在的峰值- 用户指定的信噪比级别以上的保留时间和m/z单位的指定窗口；(2)计算 动态范围，定义为整个数据集中最强烈的检测信号的强度除以 最不强烈的检测信号；以及(3)通过以下方式计算多肽分离的每个维度中的峰容量 计算峰值的宽度，并将测量范围除以该宽度。的输出 软件由(1)汇总文件组成，其中包含动态范围和峰值容量测量以及其他数据 (2)仅由信号组成的MS1/MS2格式的过滤数据文件 检测到。

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 value of mass spectrometry experiments is often assessed by the quantity and quality of results, especially in proteomics experiments where the information obtained (i.e., protein identifications) is often two or more steps removed from the raw data from which it is derived. The quality of an analysis can, however, be examined prior to the lengthy postprocessing steps required to arrive at that identification (e.g. SEQUEST processing), by examining attributes of the raw data. Critical but seldom-assessed measures of the quality of mass spectrometry experiments include general measures of data quality such as dynamic range, peak capacity, and the number of detected signals of interest. We are developing software to assess these quantities globally for each data set generated on our mass spectrometers. The software takes mass spectrometry data files in the MS1 and MS2 formats as inputs and: (1) counts the number of signals detected, where a "signal" is defined as a peak found and persisting across a large percentage of consecutive mass scans within user- specified windows of retention time and m/z units and above a user-specified signal-to-noise level; (2) computes the dynamic range, defined as the intensity of the most intense detected signal in the entire dataset divided by the intensity of the least intense detected signal; and (3) computes the peak capacity in each dimension of peptide separation by computing the width of the peaks and dividing the range over which measurements are made by this width. Output of the software consists of (1) a summary file in which dynamic range and peak capacity measurements, as well as other data attributes like number of spectra, are reported; (2) a filtered data file in MS1/MS2 format consisting only of the signals detected.