Metabolomics Analytical Methods Developed based on Direct Injection Nano-electrospray Ionization Mass Spectrometry
Recently, a research group led by Prof. XU Guowang from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) integrated nano-electrospray ionization high-resolution mass spectrometry (nanoESI DI-HRMS) with data-independent acquisition (DIA), spectral-stitching method, and capillary microsampling technology, and respectively achieved high-throughput analysis of the metabolome in large-scale clinical samples and high-throughput and high-sensitivity detection of lipidome for 20 mammalian cells.
These studies were published in Analytical Chemistry on July 16 and July 22.
Chromatography-mass spectrometry is the current mainstream technique of metabolomics analysis. However, the speed of chromatographic separation limits its application in large-scale sample analysis.
DI-MS, which is high-throughput, also faces the challenges of reduced sensitivity caused by ion suppression as well as difficulty in qualification and quantitation due to the lack of chromatographic separation.
The researchers proposed a strategy for annotation and quantitation of nontargeted metabolomics data by using a spectral-stitching DI-nESI-HRMS with DIA.
The qualification was fulfilled in combination with the accurate mass, the isotopic distribution, MS/MS spectrum similarity, and precursor and product ion correlation, obtaining a qualitative accuracy rate of > 94%. The quantitation was achieved in combination with precursor ions and characteristic product ions.
"The proposed method is stable and reliable, and takes 2-3 minutes to analyze one serum sample, suitable for high-throughput analysis of the metabolome in large-scale clinical samples," said Prof. XU.
On the other hand, conventional analytical methods for studying cellular metabolism usually use millions of cells. Whereas, these methods will encounter the problem for rare cells such as circulating tumor cells, primary tumor cells, stem cells.
The researchers proposed a novel platform by using capillary microsampling combined with online lipid extraction in a 96-well plate and high-resolution spectral stitching nanoESI DI-MS, achieving the detection of more than 500 lipids covering 19 lipid subclasses from 20 mammalian cells within 3 min.
The above work was supported by the National Key Research and Development Program of China, the National Natural Science Foundation of China, the Innovation Fund of DICP, and the Integration Fund of DICP-Qingdao Institute of Bioprocess Technology. (Text by XU Tianrun, Wang Lichao, and HU Chunxiu)
