A Multimodal Desorption Electrospray Ionisation Workflow Enabling Visualisation of Lipids and Biologically Relevant...

Area of Science:

• Biomedical Imaging
• Analytical Chemistry
• Pathology

Background:

• Elemental species colocation with biomolecules offers insights into metabolic dysregulation and disease pathogenesis.
• Alkali metals are linked to neurodegenerative and infectious diseases, impacting lipid metabolism.
• Conventional desorption electrospray ionization (DESI) using methanol:water delocalizes ions, hindering subsequent elemental analysis.

Purpose of the Study:

• To develop a novel solvent system for DESI that preserves elemental species localization.
• To enable multimodal imaging combining molecular and elemental analysis on the same tissue section.
• To improve signal-to-noise ratios for lipid detection in molecular imaging.

Main Methods:

• A new solvent system (50:50 methanol:ethanol) was developed for DESI electrospray.
• The new solvent was benchmarked against the traditional methanol:water system.
• The developed multimodal imaging workflow was applied to a lung tissue section with tuberculosis.

Main Results:

• The methanol:ethanol solvent system prevented delocalization of elemental species.
• Elemental mapping could be performed on the same tissue section after DESI.
• The methanol:ethanol solvent yielded improved signal-to-noise ratios for specific lipids compared to methanol:water.
• The workflow demonstrated applicability to elementally rich samples, such as tuberculosis granulomas.

Conclusions:

• A novel DESI solvent system enables correlative molecular and elemental imaging of tissues.
• This approach overcomes limitations of previous DESI methods regarding elemental analysis.
• The developed multimodal imaging workflow enhances the study of metabolic pathways in diseases.