Abstract

Microfabricated fluidic devices (microchips) may allow a paradigm shift that greatly enhances the ability to acquire chemical and biochemical information similar to the ways in which the transistor and integrated circuit have influenced access to electronically coded information[l,2]. Our work on moving conventional bench-top liquid phase assays to microfabricated fluidic devices will be described. The implementation of chemical separation strategies on microfabricated platforms is a key element of this so-called lab-on-a-chip technology. Many separations concepts have now been demonstrated on microfabricated structures, including capillary electrophoresis, capillary gel electrophoresis, micellar electrokinetic capillary chromatography, open channel electrochromatography, solvent programmed micellar electrokinetic capillary chromatography[3] and open channel electrochromatography[4], free flow electrophoresis, and isoelectric focusing. In most cases, these separation techniques were transferred from conventional approaches to microstructures with increased levels of performance. Moreover, microfabricated fluidic structures provide the added advantage of allowing monolithic integration of chemical processing functional elements with essentially zero dead volume interconnects. Chemical processing elements that have been integrated with chemical separations on microchips include pre-and post-separation derivitization, enzymatic digestion[5], polymerase chain reaction amplification, antigenic reactions[6], and preconcentration by stacking, solid phase extraction, and electrokinetic accumulation on a microfabricated membrane[7]. Fundamental advantages and disadvantages of microfabricated fluidic devices will be discussed.

© 2000 Optical Society of America