MALDI Imaging Mass Spectrometry – A Novel Approach in Biomedical Research of Tissues

Matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) is a powerful tool for investigating the spatial distribution of proteins and small molecules within biological specimen. This technique combines the potential of MALDI-ToF mass spectrometry with the ability to scan series of pixels across the surface of tissues, which generates multiplex space-correlated mass spectra. Numerical processing of the data allows visualization of specific molecular species and their correlation with histological image of the tissue. Hence, IMS is a multiplex untargeted analysis that enables characterization of tissue regions based on their endogenous biomolecular content. The major advantage of this technique is its potential to define tissue regions based on their molecular profiles independently of their histological and morphological characteristics given by traditional tools. IMS can detect potential cancer foci within histologically normal tissue, reveal intra-tumor heterogeneity or altered protein expression at tumor/normal tissue interface zones. IMS is an emerging technology that could fill gaps in the knowledge of spatial nature of a disease allowing better understanding of connections between structure and molecular processes.