Demonstrating voxel-by-voxel (v×v) single-point calibration in liver tissue by IR-MALDESI quantitative MSI

The quantification of glutathione (GSH) on a per-voxel basis was achieved by homogenously spraying a known amount of stable isotope labeled glutathione (SIL-GSH) on a microscope slide. Next, liver sections were mounted on top of the coated slides and imaged using IR-MALDESI MSI. Statistical analysis has shown high precision for V×V quantification over a wide concentration range, but the accuracy of this method is currently limited due to the sprayer configuration. Results support the feasibility of V×V quantification as evidence by concentration heatmaps. Additionally, voxel-based quantification provides benefits such as high specificity, straightforward sample preparation, and promising initial statistics analysis which will be advantageous for future qMSI studies.