Sampling and monitoring in bioprocessing using microtechniques

In this review we describe aspects of interactions between bioreactors and analytical systems including microsystems. Principles of bioprocess monitoring are summarized, before we focus on the miniaturization of sampling systems guaranteeing bioprocess sterility and providing analytical systems with a liquid sample. The application of negative dielectrophoresis as a new principle for cell retention in a sampling system is described followed by theoretical aspects and results. Properties of micromachined silicon membranes as filters for sampling systems and for biosensor protection are discussed.