Phystech School of Biological and Medical Physics, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russian Federation.
Outpatient department, Federal State Autonomous Institution «N.N. Burdenko National Scientific and Practical Center for Neurosurgery» of the Ministry of Healthcare of the Russian Federation, Moscow, Russian Federation.
J Mass Spectrom. 2021 Apr;56(4):e4640. doi: 10.1002/jms.4640. Epub 2020 Aug 14.
Recently, mass-spectrometry methods show its utility in tumor boundary location. The effect of differences between research and clinical protocols such as low- and high-resolution measurements and sample storage have to be understood and taken into account to transfer methods from bench to bedside. In this study, we demonstrate a simple way to compare mass spectra obtained by different experimental protocols, assess its quality, and check for the presence of outliers and batch effect in the dataset. We compare the mass spectra of both fresh and frozen-thawed astrocytic brain tumor samples obtained with the inline cartridge extraction prior to electrospray ionization. Our results reveal the importance of both positive and negative ion mode mass spectrometry for getting reliable information about sample diversity. We show that positive mode highlights the difference between protocols of mass spectra measurement, such as fresh and frozen-thawed samples, whereas negative mode better characterizes the histological difference between samples. We also show how the use of similarity spectrum matrix helps to identify the proper choice of the measurement parameters, so data collection would be kept reliable, and analysis would be correct and meaningful.
最近，质谱方法显示出在肿瘤边界定位中的实用性。必须了解和考虑研究和临床方案之间的差异，例如低分辨率和高分辨率测量以及样品储存，以便将方法从实验室转移到临床。在这项研究中，我们展示了一种简单的方法来比较不同实验方案获得的质谱，评估其质量，并检查数据集是否存在离群值和批次效应。我们比较了使用在线盒式萃取在电喷雾电离之前获得的新鲜和冷冻解冻的星形胶质细胞瘤样本的质谱。我们的结果揭示了正离子模式和负离子模式质谱对于获取有关样品多样性的可靠信息的重要性。我们表明，正离子模式突出了质谱测量方案之间的差异，例如新鲜和冷冻解冻的样本，而负离子模式则更好地表征了样本之间的组织学差异。我们还展示了如何使用相似谱矩阵来帮助确定测量参数的正确选择，以便保持数据采集的可靠性，并且分析是正确且有意义的。
