Figure 1

Figure 1

MALDI MSI workflow in D. rerio and D. magna. (a) Workflow for the precise analysis of lipid patterns visualizing anatomical features within neuronal and non-neuronal compartments. For sample preprocessing the adult zebrafish was cut cranial to the anal fin. The prepared sample was embedded in carboxymethylcellulose (CMC) and sagittal cryosections were prepared as indicated by the yellow line. Sections were covered with 4-Nitroaniline (pNA) matrix and MALDI MSI experiments were carried out in positive ion mode with 25 µm step size. (b) Workflow for the spatial localization of a command neuron in brain sections. Adult zebrafish were cut cranial to the anal fin and fixated in paraformaldehyde (PFA). After removal of the brain, it was fixated in sucrose and subsequently was embedded in CMC. Coronal cryosections were prepared as indicated by the red line. Brain sections (70 µm) were coated with pNA matrix and MALDI MSI measurements were carried out in positive ion mode with 5 µm step size. Prior to matrix application the sections were investigated by fluorescence microscopy to ensure the presence of the soma of the command neuron. (c) Workflow revealing the spatial distribution of lipids in whole body sections of D. magna. The sample was directly embedded in gelatin solution (8%) and sections (of 18 µm thickness) were prepared and coated with pNA matrix. MALDI MSI experiments (10 µm step size) were performed as described before.