Imaging Biological Tissues at High Chemical and Spatial Resolutions Using Mass Spectrometry

Imaging mass spectrometry is a powerful analytical technique for analyzing the spatial lipidome. This technology enables the visualization of molecular pathology directly in tissues by combining the specificity of mass spectrometry with the spatial fidelity of microscopic imaging. This label-free methodology has proven exceptionally useful in research areas such as cancer diagnosis, diabetes, and infectious disease. However, state-of-the-art experiments stress the limits of current analytical technologies, necessitating improvements in molecular specificity and sensitivity in order to answer increasingly complicated biological and clinical hypotheses. Especially when studying lipids, many isobaric (i.e., same nominal mass) and isomeric (i.e., same exact mass) compounds exist that complicate spectral analysis, with each structure having a potentially unique cellular function. The Prentice Lab develops instrumentation and novel gas-phase reactions to provide unparalleled levels of chemical resolution. These gas-phase transformations are fast, efficient, and specific, making them ideally suited for implementation into imaging mass spectrometry workflows. For example, these workflows have enabled the identification of multiple sn-positional phosphatidylcholine isomers, the separation of isobaric phosphatidylserines and sulfatides, and the identification of fatty acid double bond isomers using a variety of charge transfer and covalent ion/ion reactions as well as ion/electron and ion/photon reactions. Working with biologists and clinicians, we then leverage these novel imaging technologies to understand the molecular events associated with important problems in human health, including infectious disease, diabetes, and neurodegenerative diseases.