EXPRESS: Two-Trace Two-Dimensional (2T2D-COS) in the Analysis of Brain Tissue Sample Preparation Method

Raman spectroscopy is widely used in biomedicine due to its non-invasive nature and the large amount of information it contains. This technique allows for the analysis of changes in lipid composition and concentration, which may be useful diagnostic parameter. These changes may appear at an early stage of neurodegenerative diseases and brain tumours. In addition, Raman spectroscopy allows measurements to be taken on tissues that have not been previously preserved. Therefore, it is important to investigate and select an appropriate method of sample storage in order to obtain Raman spectra of the highest possible quality. There are no clear guidelines in the currently available literature on how to prepare brain tissue samples to obtain the highest possible spectral quality. The aim of this study was to investigate the influence of an important parameter - the storage temperature of rat brain tissue on the quality of the spectrum. Based on a review of the literature, three methods of storing brain tissue were selected. The obtained Raman spectra were pre-processed and averaged. 2T-2D analysis was performed, comparing spectra differing in the way the tissue was stored before measurement.. Based on the 2T-2D maps, differences were identified and discussed.