USTC Achieves New Progress in MSI Methodology
Mass spectrometry imaging (MSI) is a new molecular imaging technology which could obtain the spatial distribution characteristics of multiple molecules simultaneously by scanning biological samples directly.
A common atmospheric imaging technology of this type is DESI-MSI. Though with the advantages of fluorescence-free labeling and no-need of complex sample pretreatment, the main drawbacks of this method are polar discrimination and strong ion suppression, which are not suitable for all the object systems to be measured.
USTC Prof. PAN Yang with his team from National Synchrotron Radiation Laboratory (NSRL) recently developed a DESI-based secondary photoionization mass spectrometry (DESI-PI-MSI) technology, and in collaboration with Prof. XIONG Wei, from School of Life Sciences, conducted mass spectrometry imaging of brain, and spinal cord sections from model mice.
Principle Diagram of the DESI-PI-MSI Device. (Image by NSRL and School of Life Sciences)
The key of DESI-PI-MSI technology is to lead a photoionization system and an efficient ion transport pipeline (as the first image shows) into the DESI spray device. It could realize high sensitivity imaging of various polar and non-polar components by opening and closing the optical and electrical source.
Studies have shown that DESI-PI-MSI could significantly improve the sensitivity in both positive and negative ion modes, even for some highly polar neurotransmitters and lipids, thus laying a foundation for high sensitivity detection of biomarkers and accurate imaging of drug metabolism, which is demonstrated in the following image.
DESI-MSI and DESI-PI-MSI obtained mass spectrometry and imaging of brain slices from mice under negative ion mode. (Image by NSRL and School of Life Sciences)
On the existing devices, Prof. PAN’s team has further designed differential pumping system and ion transport pipeline for synchrotron radiation mass spectrometry imaging, further improving the application scope of photoionization mass spectrometry imaging and expanding the application field of synchrotron radiation. At present, the new system has been installed and debugged to meet the design requirements.
On May 22th, the results of this study were published in Analytical Chemistry, the top journal in the field of analytical chemistry, and applied for invention patents. The research work was supported by the Ministry of Science and Technology, the Fund Committee and the Hefei Science Center, CAS.
(USTC News Center, written by YANG Xinqi, Edited by HU Dongyin)
