Precast Gelatin-Based Molds for Tissue Embedding Compatible with Mass Spectrometry Imaging

Area of Science:

• Biomedical Imaging
• Analytical Chemistry
• Neuroscience

Background:

• Matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI) requires robust tissue preparation for accurate molecular analysis.
• Brain tissue's high fat content presents challenges for cryosectioning and structural preservation.
• Current methods using Optimal Cutting Temperature (OCT) compound can introduce interferences and limit analyte analysis.

Purpose of the Study:

• To develop a novel tissue embedding method for MALDI-MSI compatible with both fresh and fixed brain tissue.
• To overcome the limitations of existing methods, including structural integrity and background interference.
• To enable broader analyte detection and preserve brain topography during sample preparation.

Main Methods:

• Development of precast gelatin-based molds for embedding whole mouse brains.
• Flash-freezing of embedded tissue for enhanced rigidity.
• Cryosectioning of frozen tissue for subsequent MALDI-MSI analysis.

Main Results:

• The gelatin mold method provides structural support for fragile brain tissue during cryosectioning.
• Elimination of OCT compound reduces background interference in MALDI-MSI.
• The method is compatible with both fresh and fixed tissues, allowing for diverse analyte analysis.

Conclusions:

• Gelatin-based embedding offers a superior alternative for preparing brain tissue for MALDI-MSI.
• This technique improves sample quality, enabling more comprehensive molecular imaging of the brain.
• The method facilitates the study of a wider range of analytes in brain tissue with preserved structural integrity.