NIH Research Festival
Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) is a versatile analytical technique that can be adapted to target a diverse range of biomolecules. Here, the use of MALDI-TOF MS as a tool for targeted immunochemical profiling, as well as bottom-up spatial analysis of analytes, is discussed. Our unit, in collaboration with the Laboratory of Immunoregulation at NIAID, uses MALDI-TOF MS to profile IgG3 glycosylation in HIV-infected chronically viremic and healthy individuals. Following chemical glycosylation and spotting onto a target plate, the mass distribution of four major glycoforms is analyzed with MALDI-TOF MS. The resulting glycosylation patterns are then compared. Alternatively, through a non-targeted, bottom-up approach, MALDI-TOF can be adapted for tissue imaging to achieve comprehensive spatial analysis of histological samples. During the MALDI imaging process, tissue slides are subjected to a series of washes and coated with specialized matrices to favor lipid, peptide, or protein expression. Following imaging, our unit uses statistical analysis software to generate heat maps and segmentation of the tissue. Based on these results, droplet probe extraction is used to isolate analytes from regions of interest. Liquid chromatography-mass spectrometry (LCMS) is used to further break down analytes into their fragment ions and provide identification of unknown species from proteomic and lipidomic databases. Through these methods, MALDI-TOF MS can quickly provide valuable analytical insight for various sample types and targets.
Scientific Focus Area: Immunology
This page was last updated on Monday, September 25, 2023