Chapter 5: Sample Preparation of Biological Tissues for MALDI-MSI

Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) can be used to visualize molecular distributions in tissues. This spatial information provides a rich source of biological information and pathological insights. However, sample preparation is a crucial step for successful results. Many factors can influence these results such as sample collection, sample storage, embedding, sectioning, washing or matrix application steps. During the sample preparation process, the molecular spatial distribution needs to be maintained while extraction efficiency by the MALDI-matrix should be sufficient to reach the required sensitivity. The balance between these two is often a challenge. In this chapter, we will discuss MALDI-MSI sample preparation workflows from metabolomics to proteomics and tackle the most crucial steps therein.