Conclusions
Wet-interface matrix deposition devices for MALDI mass spectrometry
imaging are convenient and highly effective in use. Proper optimization
of parameters such as the number of matrix layers and the nozzle height
over the sample allows substantial improvement of the analysis
parameters. Thus, the analysis of precious biological samples can be
performed with the best possible quality. However, the care must be
taken during the matrix selection to visualize the molecules of interest
without losing their spatial distribution. Moreover, our analysis shows
that the ion map obtained with the aid of a particular matrix might
differ significantly with the use of another. So, care must be taken
when comparing the results and drawing biological conclusions from such
analyses.
Funding: This work was supported by the Polish National Science
Center (NCN) grant number 2018/29/B/NZ4/02243 to ABK, statutory funds
from the Maj Institute of Pharmacology at the Polish Academy of Sciences
to PM, subsidy no 16.16.160.557 of the Polish Ministry of Science and
Education to ABK, PS, PK and IK.
Institutional Review Board Statement: The study was conducted
according to the guidelines of the Declaration of Helsinki and approved
by the Local Ethics Committee (agreement number 137/2018).
Data Availability Statement: All the data present in the study
are available upon request from the corresponding author.
Conflicts of Interest: The authors declare no conflict of
interest. The funders had no role in the design of the study; in the
collection, analyses, or interpretation of data; in the writing of the
manuscript, or in the decision to publish the results.