Mass spectrometric tools for cell and tissue studies.

Mass spectrometry (MS) is a powerful tool for identification and quantitation of organic molecules from various matrices, especially when combined with liquid chromatography (LC). The aim of this review is to present different MS techniques and methods which can be utilized in drug and metabolism studies using cells and tissues. The first part focuses on the use of LC/MS in permeability studies across cell lines as well as in ABC transporter protein experiments. The second part describes the utilization of MS in drug metabolism studies using cell lines. The third part presents a relatively new application area of MS, namely mass spectrometric imaging (MSI) or imaging mass spectrometry (IMS). Several different MSI techniques can be used for characterization of surfaces, in terms of abundance of proteins and peptides but also small molecules, such as drug compounds and their metabolites, at the surface. The final part gives a review of MS based techniques for direct analysis of cell contents.