# Photochemical Tissue Modification for MALDI Mass Spectrometry Imaging

> **NIH NIH R43** · LASER BIOANALYTICS LLC · 2024 · $304,196

## Abstract

Project Summary/Abstract
The goal of this project is to develop a prototype instrument and techniques for photochemical patterning
of lipids in tissue sections for mass spectrometry structural analysis and imaging. The proposed instrument
uses focused laser beams to drive photochemical reactions in the tissue that tag lipid double bond locations.
The tissue is then analyzed using a commercial matrix-assisted laser desorption ionization (MALDI) mass
spectrometer. Fragmentation of the lipids by tandem mass spectrometry produces diagnostic ions that reveal
the lipid double bond location that is otherwise indiscernible.
Lipids are important cellular components and important in the diagnosis and treatment of many diseases.
Mass spectrometry is a powerful method for identifying and quantifying lipids in tissue and mass
spectrometry imaging can localize lipids in tissue at spatial resolution approaching cellular precision. One
of the greatest challenges in mass spectrometry of lipids is determining the structure of these structurally
and biochemically diverse compounds. Determining the location of double bonds in unsaturated lipids can
be accomplished using photochemical reactions such as the Paterno-Büchi carbonyl cycloaddition reaction
which forms products that readily fragment in mass spectrometry experiments to reveal lipid structure. The
device to be developed in this project allows photochemical reactions to be performed on tissue sections
with selected patterns that facilitate identification and distribution of lipids.
This project will develop new technology for patterned tissue photochemistry for mass spectrometry
imaging. The process is general and applicable not only to lipid identification but can also be applied to
protein photochemistry and structural analysis, lipid and protein photo-crosslinking, and photochemical
cage release reactions. The target commercial potential for this technology is clinical and research
laboratories using MALDI mass spectrometry imaging. This technology provides capabilities that are not
commercially available in any device and the system can be directly integrated into current mass
spectrometry imaging workflows.

## Key facts

- **NIH application ID:** 11005360
- **Project number:** 1R43GM156259-01
- **Recipient organization:** LASER BIOANALYTICS LLC
- **Principal Investigator:** Kermit King Murray
- **Activity code:** R43 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $304,196
- **Award type:** 1
- **Project period:** 2024-09-15 → 2026-09-14

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/11005360

## Citation

> US National Institutes of Health, RePORTER application 11005360, Photochemical Tissue Modification for MALDI Mass Spectrometry Imaging (1R43GM156259-01). Retrieved via AI Analytics 2026-05-27 from https://api.ai-analytics.org/grant/nih/11005360. Licensed CC0.

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