Envirostat technologies for time resolved single cell analysis in contactless controlled microenvironments

The complex biochemical mechanisms in cells have evolved over millions of years of evolution. Most cellular research about intracellular mechanisms of individual cells was analyzed with populations. The averaged data from millions of cells allow no conclusion to e. g. cell-cycle or cell-age dependent mechanisms which makes single cell analysis indispensable. In contrast to a snapshot analysis by flow cytometry, a controlled cultivation of a single bacterium would allow to analyze cellular responses to microenvironmental controlled stimuli. But how to cultivate and analyze a few micrometers large living bacterium in controlled microenvironments? Driven by this pivotal question microfluidic and micro-electronic procedures were developed on glass chips, which enable for the first time contactless isolation and reversible fixation of a single bacterium in stream of medium by negative dielectrophoresis. Especially miniaturized octupole electrodes enabled high resolution and cell type independent manipulations with new analytical possibilities. A critical issue for the fluidic single bacterium manipulations was the connection from macro to microfluidics. Hence, parallel to chip developments a novel „on-tube-seal“ was developed. Adhesion analysis allowed the selection of cell repellent coatings and optimized cell isolation. Finally, individual cells of Corynebacterium glutamicum were analyzed in controlled microenvironments. The comparison to population analysis data showed faster growth in a controlled microenvironment and unprecedented bioanalytical resolution when comparing single bacterium cultivations in different microenvironments. In summary, the in this thesis developed technologies enable to study the smallest unit of life, the single cell with novel possibilities.