Recent developments in electrokinetically driven analysis on microfabricated devices

This review is devoted to the rapid developments in the field of microfluid ic separation devices in which the flow is electrokinetically driven, and w here the separation element forms the heart of the system, in order to give an overview of the trends of the last three years. Examples of microchip l ayouts that were designed for various application areas are given. Optimiza tion of mixing and injection strategies, designs for the handling of multip le samples, and capillary array systems show the enormous progress made sin ce the first proof-of-concept papers about lab-on-a-chip devices. Examples of functional elements for on-chip preconcentration, filtering, DNA amplifi cation and on-chip detection indicate that the real integration of various analytical tasks on a single microchip is coming into reach. The use of mat erials other than glass, such as poly(dimethylsiloxane) and polymethylmetha crylate, for chip fabrication and detection methods other than laser-induce d fluorescence (LIF) detection, such as mass spectrometry and electrochemic al detection, are described. Furthermore, it can be observed that the separ ation modes known from capillary electrophoresis (CE) in fused-silica capil laries can be easily transferred to the microchip platform. The review conc ludes with an overview of applications of microchip CE and with a brief out look.