Spatial compartmentalisation is a prerequisite for the creation of living matter. Without the existence of clearly defined borders, differentiation and diversity at the cellular level would not be possible. Most scientific disciplines that deal with dissolved mols. are concerned with the same problem of subdividing solns. in miniaturized autonomous units, either to increase the functional complexity of a system, reduce reagent consumption, monitor fast chem. kinetics or even to study single-mols. I will report on our recent progress that allows the massively parallel isolation of attoliter (10 -18 l) sized artificial and native, cell-derived vesicles and their self-assembled positioning with 100-nm precision in ordered arrays on surfaces. The broad application for investigating (bio)chem. reactions and cellular signaling processes in individual containers by elec. and optical techniques will be discussed. The biol. processes which will be presented are mediated on and across cellular membranes via transmembrane receptors such as transport-, channel-proteins or G protein-coupled receptors to mention some important examples. Our novel approaches are important for the elucidation of the mol. basis of receptor function and signal transduction processes as well as for applications in the field of screening for novel therapeutic compds. [on SciFinder (R)]