Intracellular drug localization analysis by live single-cell mass spectrometry

Abstract

There are increasing demands to study the molecular and cellular behavior of a single-cell precisely because the current knowledge in life science was obtained using bulk populations of cells with little information on the localization or environment of cells. We developed the “Live Single-cell Mass Spectrometry” method which allows direct analysis of xenobiotics and endogenous compounds in a living cell. This method is composed of two steps; 1. cellular contents are captured from a living cell using a platinum coated glass microcapillary (i.d. 3 μm) under microscopic observation, and 2. the capillaries are directly subjected to off-line nanoelectrospray ionization of the sampled cellular contents such as cytosol or organelles for mass spectrometry. This system is capable of automatically sampling either a targeted whole living cell or an organelle based on a captured 3D confocal bioimage. In this study, we analyzed the localization of amiodarone and its metabolite in amiodarone-treated single HepG2 cells.