Matrix Phase Fractionation: Investigating the Compromise Between Dynamic Range Of Analyte Extraction and Spatial Resolution In Imaging Mass Spectrometry.

RATIONALE MALDI-MSI has seen rapid development in recent years and as such is a becoming an important technique for the mapping of biomolecules from the surface of tissues. One key area of development is the optimisation of analyte extraction by using modified matrices or mixes of common ones. METHODS A series of serial sections were prepared for lipid MSI by either dry coating (sublimation) or by wet spray application of several matrices. These samples were then evaluated for analyte extraction, delocalisation and dynamic range. RESULTS We have shown that the spraying and sublimation methods of matrix application can be used complementarily. This creates large datasets, with each preparation method applied narrowly and then interpreted as a "fraction" of the whole. One combined the dynamic range is significantly increased. Re have dubbed this technique "Matrix Phase Fractionation" CONCLUSIONS: We have found that, by utilising "Matrix Phase Fractionation" for the detection of lipids in brain tissue, it is possible to create a significantly more comprehensive data set that would otherwise be impossible with traditional "single run" workflows.