## 3 Results  
Figure 2 presents the stitched images obtained with the 5\(\times\) objective. Column 1 shows images of the H&E-stained sample recorded with the transmitted light brightfield mode. The incident light brightfield mode was used to take photographs of the unstained tissue section (column 2). The stitched images are the results from scan number 1 (incident light mode) and 9 (transmitted light mode) within the measurement sets for tissue analysis (Table 2). Since the brain was cut in the coronal plane, the tissue section showed symmetric brain structures that were mirrored on the longitudinal fissure (dashed line, Figure 2(1a,2a)). Consequently, it was sufficient to measure one cerebral hemisphere for the global scans. The global scan's result of the H&E-stained sample is illustrated in Figure 2(1a). The corresponding scan of the unstained sample is shown in Figure 2(2a). Both images provide an overall overview of the cryosections. The main parts within the tissue sections were examined by experienced researchers trained in mouse anatomy and regions of interest were identified and marked accordingly (see Figure 2(1a,2a)). The annotations are in accordance with the labelling in the Allen Brain Atlas [66,67].Besides GM and WM, ventricles can be observed. These are cavities filled with cerebrospinal fluid [68]. The lateral and the 3 rd ventricle are highlighted in black. The corpus callosum as well as the internal capsule are WM. Those regions are marked in green. GM, the hippocampus and the cortex, is highlighted in red. Figure 2(1b,2b) show smaller image sections containing portions of the cortex, corpus callosum, and hippocampus. These stitched images are the results of the local scan using  
Figure 2: Stitched images (5\(\times\) objective) of the stained (**1**) and unstained (**2**) sample. Results of (**a**) global and (**b**) local scan; photographs: 10 \(\times\) 12 (**1a**), 11 \(\times\) 12 (**2a**), 2 \(\times\) 2 (**1b,2b**) (see text for details). the 5\(\times\) magnification. These smaller areas can be localized by the orange frame within the global images (Figure 2(1a,2a)). Furthermore, artefacts such as an air bubble and a scratch facilitate the visual assignment within the unstained tissue section (Figure 2(2b)). Although the stitched images of the unstained sample allow a visual differentiation from GM and WM, staining is necessary to highlight cellular structure. The cell density of the WM is lower compared to GM. This fact is confirmed by the images of the H&E-stained tissue section that show an accumulation of the dark colored cells in the GM. The area of the local scan using the microscopic modes and the 20\(\times\) objective is highlighted by the bright blue frame (see Figure 2(2b)). Spectra acquisition with the molecule-specific but time-consuming Raman spectroscopy and the VIS/NIR spectroscopy was performed within the smaller ROI (purple frame). The total measuring times, including instrumentation time (t\({}_{\text{stage}}\), t\({}_{\text{readout}}\), t\({}_{\text{transfer}}\)), resulted in 12 min for VIS spectra and 16 min for NIR spectra. In contrast, the total time to acquire Raman spectra was nearly 3 h. Taking photographs took less than 1 min for each modality. The total measuring time varied from 30 min for incident light brightfield microscopy to 90 min for Raman spectroscopy. The respective integration times and step sizes are listed in Table 2.  
The subsequent evaluation (Figure 3) displays images of the unstained tissue section's brain structure based on the different modalities. These are the results of the global scan and the local scan obtained during scan number 2-8 within one set of measurements.