Assessing the Energy Status of Low Numbers of Mammalian Cells by Capillary Electrophoresis-Mass Spectrometry.

Capillary electrophoresis-mass spectrometry (CE-MS) employing a sheathless porous tip interface has become a strong analytical tool for the efficient profiling of highly polar and charged metabolites in volume/material-restricted biological samples. As more and more metabolomics studies are (intrinsically) dealing with low numbers of mammalian cells, it would be important to use an additional performance metric to effectively evaluate the sampling and sample preparation procedure, in particular quenching. An established parameter to assess the sampling and sample preparation quality when working with cell cultures is the adenylate energy charge (AEC), which represents an index of the energy state of a cell. In this protocol, a CE-MS strategy is proposed for the reliable determination of the adenylate energy charge (AEC) in metabolomics studies dealing with low numbers of mammalian cells.