Chemical and topographical 3D surface profiling using atmospheric pressure LDI and MALDI MS imaging

Kompauer, Mario; Heiles, Sven; Spengler, Bernhard

doi:10.1038/protex.2017.103

Cited by 6 publications

(1 citation statement)

References 32 publications

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“…Following on these results, the group has diverted their interest towards MALDI MS Imaging, albeit exploiting instrumentation innovation enabling 3D topographical molecular maps as recently reported by the Spengler's group [31]. Despite the spatial resolution offered by this technology may not presently be suitable for determining the mechanism of deposition of blood and fingermarks, in the authors' opinion, this technological innovation appears to be the most suitable analytical tool to investigate to date.…”

Section: Resultsmentioning

confidence: 99%

Investigation of infinite focus microscopy for the determination of the association of blood with fingermarks

et al. 2018

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The determination of the type of deposition mechanism of blood within fingermarks at the scene of violent crimes is of great importance for the reconstruction of the bloodshed dynamics. However, to date, evaluation still relies on the subjective visual examination of experts. Practitioners encounter three types of scenarios in which blood may be found in fingermarks and they refer to the following three deposition mechanisms: (i) blood marks, originating from a bloodied fingertip; (ii) marks in blood, originating from a clean fingertip contacting a blood contaminated surface; (iii) coincidental deposition mechanisms, originating from a clean fingertip contacting a clean surface, leaving a latent fingermark, and subsequent contamination with blood.. The authors hypothesised that, due to differences in distribution of blood in the furrows and on the ridges, the height of blood depositions on the ridges and furrows (and their relative proportions), will differ significantly across the three depositions mechanisms. A second hypothesis was made that the differences would be significant and consistent enough to exploit their measurement as a quantitative and objective way to differentiate the deposition mechanisms. In recent years, infinite focus microscopy (IFM) has been developed, allowing for the computational generation of a 3D image of the topology of a sample via acquisition of images on multiple focal planes. On these bases, it was finally hypothesised that the application of this technique would allow the distinction of deposition mechanisms (i) to (iii) A set of preliminary experiments were designed to test whether IFM was "fit for purpose" and, subsequently, to test if any of the three deposition mechanisms scenarios could be differentiated. Though IFM enabled the analysis of tape lifted samples with some success, for samples produced and analysed directly on the surface of deposition, the results show that the measurements from any scenario will be highly dependent on the original surface of deposition (both in terms of its nature and of the variable exposure to environment); as crime scenes exhibit a wide range of possible relevant surfaces of deposition, the technique showed to not have the desired wide appeal for inclusion into a standardised set of protocols within a routine crime scene workflow.

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Section: Resultsmentioning

confidence: 99%

Investigation of infinite focus microscopy for the determination of the association of blood with fingermarks

et al. 2018

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Metabolipidomic changes induced by dermal nickel penetration determined in an ex vivo porcine ear skin model

Rezaei,

Ganashalingam,

Schindler

et al. 2024

Rapid Comm Mass Spectrometry

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RationalNickel is one of humans' most prevalent triggers of allergic contact dermatitis. However, the underlying mechanisms of this allergy still need to be fully understood. One aspect that has yet to be explored is the direct impact of common metal allergens on the skin's metabolites and lipids composition.MethodOur study employed matrix‐assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) to analyze spatially resolved metabolic alterations induced by nickel exposure. Cross‐sections of ex vivo porcine ear skin exposed to increasing nickel (II) ion concentrations (17–167 μg/cm2) were measured with an AP‐SMALDI5 AF ion source coupled to Q Exactive HF Orbitrap mass spectrometer. Additionally, the penetration of nickel ions into the skin was observed through its pink complexation with dimethylglyoxime under light microscopy.ResultsFor nickel ion concentrations up to 84 μg/cm2, most nickel ions were stopped within the stratum corneum, while only a very small proportion of nickel ions penetrated the viable epidermis and dermis. Stratum corneum locations with high nickel ion concentrations showed a decrease in arginine and ceramides. Furthermore, several phosphatidylcholine and sphingomyelin species were found to be downregulated in the viable epidermis and dermis due to the nickel exposure.ConclusionNickel penetrates at a trace level into the viable skin and induces severe metabolomic and lipidomic changes in the stratum corneum, epidermis, and dermis, indicating a change in the skin (barrier) function. These findings contribute to a deeper understanding of nickel‐induced skin allergies and provide a solid foundation for further research.

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High resolution mass spectrometry for single cell analysis

Nisar

Zhao

2020

International Journal of Mass Spectrometry

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Chemical and topographical 3D surface profiling using atmospheric pressure LDI and MALDI MS imaging

Cited by 6 publications

References 32 publications

Investigation of infinite focus microscopy for the determination of the association of blood with fingermarks

Investigation of infinite focus microscopy for the determination of the association of blood with fingermarks

Metabolipidomic changes induced by dermal nickel penetration determined in an ex vivo porcine ear skin model

High resolution mass spectrometry for single cell analysis

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