Official websites use. Share sensitive information only on official, secure websites. DU and JL designed the study and co-wrote the manuscript. DU performed imaging experiments and processed the data. RY and MY contributed to data collection. DMS developed approaches for processing and visualization of the imaging data. DU performed the imaging experiments and processed the data.
RY and MY also contributed in the data collection. Corresponding author: Julia Laskin, Tel: , jlaskin purdue. Simultaneous spatial localization and structural characterization of molecules in complex biological samples currently represents an analytical challenge for mass spectrometry imaging MSI techniques. In this study, we describe a novel experimental platform, which substantially expands the capabilities and enhances the depth of chemical information obtained in high spatial resolution MSI experiments performed using nanospray desorption electrospray ionization nano-DESI.
Specifically, we designed and constructed a portable nano-DESI MSI platform and coupled it with a drift tube ion mobility spectrometer-mass spectrometer. Collision cross-section measurements provide unique molecular descriptors of molecules observed in nano-DESI-IM-MSI necessary for their unambiguous identification by comparison with databases.
Meanwhile, isomer-specific imaging reveals variations in the isomeric composition across the tissue. Furthermore, ion mobility separation efficiently eliminates isobaric and isomeric interferences originating from solvent peaks, overlapping isotopic peaks of endogenous molecules extracted from the tissue, and products of in-source fragmentation, which is critical to obtaining accurate concentration gradients in the sample using MSI.
The structural information provided by the IM separation substantially expands the molecular specificity of high-resolution MSI necessary for unraveling the complexity of biological systems.
