Related Experiment Video
Updated: Jul 2, 2026
Sample Preparation for Metabolic Profiling using MALDI Mass Spectrometry Imaging
Published on: December 22, 2020
Time-dependent evolution of tissue markers by MALDI-MS imaging
Richard J A Goodwin1, Jessica C Dungworth, Stuart R Cobb
1Division of Biochemistry and Molecular Biology, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow, UK.
Abstract:
We have used MALDI-MS imaging (MALDI-MSI) to monitor the time dependent appearance and loss of signals when tissue slices are brought rapidly to room temperature for short to medium periods of time. Sections from mouse brain were cut in a cryostat microtome, placed on a MALDI target and allowed to warm to room temperature for 30 s to 3 h. Sections were then refrozen, fixed by ethanol treatment and analysed by MALDI-MSI. The intensity of a range of markers were seen to vary across the time course, both increasing and decreasing, with the intensity of some markers changing significantly within 30 s and markers also showed tissue location specific evolution. The markers resulting from this autolysis were compared directly to those that evolved in a comparable 16 h on-tissue trypsin digest, and the markers that evolved in the two studies were seen to be substantially different. These changes offer an important additional level of location-dependent information for mapping changes and seeking disease-dependent biomarkers in the tissue. They also indicate that considerable care is required to allow comparison of biomarkers between MALDI-MSI experiments and also has implications for the standard practice of thaw-mounting multiple tissue sections onto MALDI-MS targets.
Insights
Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) reveals rapid changes in tissue biomarkers upon warming. These autolysis-derived markers differ significantly from enzymatic digest markers, impacting experimental comparisons.
Area of Science:
- Biochemistry
- Analytical Chemistry
- Neuroscience
Background:
- Tissue analysis using Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging (MALDI-MSI) is crucial for molecular mapping.
- Understanding post-mortem tissue changes is vital for accurate biomarker discovery and interpretation.
Purpose of the Study:
- To investigate the time-dependent molecular alterations in mouse brain tissue upon exposure to room temperature.
- To compare the molecular markers generated by autolysis with those from enzymatic digestion.
Main Methods:
- Mouse brain tissue sections were subjected to varying periods (30 s to 3 h) at room temperature.
- Sections were refrozen, fixed, and analyzed using MALDI-MSI.
- Autolysis-derived markers were compared to markers from a 16-hour on-tissue trypsin digest.
Main Results:
- Significant time-dependent changes in the intensity of various molecular markers were observed, with some evolving within 30 seconds.
- Tissue location-specific evolution of markers was evident.
- Markers resulting from autolysis were substantially different from those obtained via trypsin digestion.
Conclusions:
- Rapid autolysis significantly alters the molecular profile of tissue samples, generating distinct markers compared to enzymatic digestion.
- These findings highlight the critical need for careful standardization in MALDI-MSI experiments to ensure comparability of results.
- The observed changes provide location-dependent information and have implications for biomarker discovery and tissue handling protocols.
