Mass Spectrometry Spatial-Omics on a Single Conductive Slide.

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Molecular Biology

Background:

• Mass spectrometry imaging (MSI) typically requires separate tissue sections for molecular identification after initial analysis.
• Laser capture microdissection (LMD) is often used for targeted molecular analysis but usually requires specific slide materials.
• Current workflows for multimodal spatial omics can be complex and time-consuming.

Purpose of the Study:

• To develop a streamlined workflow for multimodal spatial omics analysis.
• To demonstrate the feasibility of performing both matrix-assisted laser desorption ionization (MALDI)-MSI and direct proteomics on a single conductive slide.
• To enable laser capture microdissection (LMD) directly on the MSI slide while preserving protein integrity.

Main Methods:

• Utilized a single conductive glass slide for both MALDI-MSI and subsequent direct proteomics.
• Integrated LMD for targeted ablation of regions of interest directly from the conductive slide.
• Developed a workflow to preserve protein integrity after MSI and LMD for downstream proteomic analysis.

Main Results:

• Successfully performed MALDI-MSI and direct proteomics on the same tissue section mounted on a single conductive slide.
• Demonstrated that LMD can be performed on the conductive slide, ablating specific regions while maintaining protein integrity.
• Validated the preservation of protein integrity for subsequent proteomic analysis after MSI and LMD.

Conclusions:

• A single conductive slide can be effectively used for both MALDI-MSI and direct proteomics, simplifying multimodal spatial omics.
• This integrated approach reduces the need for serial tissue sections and associated experimental steps.
• The developed workflow offers a more efficient alternative for comprehensive spatial omics investigations.