FluoMALDI Microscopy: Matrix Co-Crystallization Simultaneously Enhances Fluorescence and MALDI Imaging.

Area of Science:

• Analytical Chemistry
• Biomedical Imaging
• Microscopy

Background:

• Matrix-assisted laser desorption/ionization (MALDI) imaging offers versatile, multiplexed capabilities.
• Fluorescence microscopy provides high spatial resolution and specific labeling.
• Integrating these modalities is challenging due to sample manipulation and registration issues.

Purpose of the Study:

• To develop a novel imaging technique, FluoMALDI, by co-crystallizing fluorophores with MALDI matrices.
• To enhance fluorophore brightness and amplify tissue autofluorescence for improved imaging.
• To enable seamless imaging of the exact same biological sample using both fluorescence microscopy and MALDI imaging.

Main Methods:

• Co-crystallization of fluorophores with MALDI imaging matrices.
• Application of FluoMALDI to endogenous and exogenous fluorophores.
• Demonstration of autofluorescence-based FluoMALDI on brain and kidney tissue sections.

Main Results:

• Fluorophore brightness was enhanced up to 79-fold through co-crystallization.
• FluoMALDI successfully combined fluorescence microscopy and MALDI imaging on the same tissue sections.
• The method allowed imaging of identical cells across both modalities without physical sample changes.
• Feasibility was demonstrated for both endogenous and exogenous fluorophores, as well as autofluorescence.

Conclusions:

• FluoMALDI represents a significant advancement in correlative imaging, merging fluorescence and MALDI techniques.
• The enhanced brightness and simplified registration advance structural-functional microscopic imaging.
• This technique holds promise for applications in cell biology, biomedicine, and pathology, particularly for samples with low fluorescence.