DESI analysis of mammalian cell cultures - sample preparation and method optimisation

Desorption electrospray ion source (DESI) is widely used as an MS imaging technique. It is a rapid and convenient method of surface analysis, but to date, there are methodological obstacles to its application to the analysis of cell culture. This study reported optimised conditions for the analysis of cell culture samples. Parameters such as the surface, medium removal and sample desiccation techniques were assessed as a function of output data quality. Supercharging agents, surfactants and optimal parameters for the DESI ion source were evaluated for use in cell culture analyses. Data indicated that plastic dishes or sodium glass coated with poly-L-lysine and washing cell cultures with 150 mM ammonium acetate followed by drying with inert gas were superior for DESI analyses. The addition of 1 mu M surfactin to the DESI spray solvent significantly improved the results for negative and positive ion modes. Copyright (C) 2014 John Wiley & Sons, Ltd.