دانلود رایگان مقاله انگلیسی طیف سنجی جرمی در پاتولوژی - چشم انداز برای گردش کار آینده - الزویر 2018

ABSTRACT

Mass spectrometric (MS) techniques are applied in various areas of medical diagnostics. For the detection of microbiological germs and genetic mutations, MS is a method used in routine. Since MS also allows the analysis of proteins and peptides, it seems an ideal candidate to supplement histopatholological diagnostics. Matrixassisted laser desorption/ionization time-of-flight Imaging MS links molecular analysis of numerous analytes with morphological information about their spatial distribution in cells or tissues. Herein, we review principle MS techniques as well as potential applications in pathology and discuss our vision for a future workflow.

6. Methods in mass spectrometry

Various different methods of MS including, but not limited to the following exist: MALDI profiling, MALDI-IMS, MALDI-IMS in profiling mode, MALDI MS/MS directly from tissue, LC–MS/MS and laser microdissection based LC–MS/MS [52]. In MALDI profiling, a specific region of interest is targeted and only few mass spectra are acquired. The major advantage of this approach is the speed of data acquisition. In MALDI-IMS, the whole tissue section is usually analyzed. Using this method, a comprehensive analysis of the spatial distribution of molecules is possible, but much data is acquired that might not all be relevant to the scientific question. In MALDI-IMS in profiling mode, whole tissue sections are analyzed, as by MALDI-IMS, but only specific regions of interest are selected for data analysis. This approach increases the speed of data acquisition and reduces the amount of data for analysis. For classification purposes, this method is usually recommended. Spectra acquired by MALDI methods are composed of peaks representing m/z values. In order to identify these m/z species and to assign peptides to these values, subsequent analyses have to be performed. In brief, either direct identification on the respective tissue section (MALDI MS/MS), or analysis by liquid based MS (LC–MS/MS) can be done. Laser microdissection followed by LC–MS/MS is an advanced technique with the ability to detect > 1000 proteins from samples containing < 3000 cells. However, using this technique, information on spatial distribution of molecules is reduced. Based on the scientific or diagnostic question, the appropriate method has to be selected. For a more detailed description of the methologies, various reviews are available in the literature [3,12,21,23,36,47,48].