ABSTRACT
Capillary electrophoresis (CE) has been reviewed extensively for a variety of applications [1]. The technique provides fast separation times and small sample requirements; however, CE is a serial technique that significantly limits throughput. To address this, capillary array electrophoresis, in which separations are performed in an array of parallel silica capillaries, was introduced by Mathies [2] and subsequently has been used to perform high-speed, high-throughput deoxyribonucleic acid (DNA) sequencing [3, 4] and DNA fragment sizing [5]. This method has proven to be an invaluable technique for the completion of the human genome project. However, sample introduction into a large number of capillaries and the physical manipulation of these capillaries can be difficult and cumbersome. The miniaturization of capillary electrophoresis onto a microchip was thus realized in the early 1990s [6] and miniaturization has been used to increase performance by reducing analysis times and reagent volumes [6
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9]. Since then, extensive advances have been made in the area of microchip technology, allowing for the analysis of a variety of substances including amino acids [10], small drug molecules [11], peptides [12], oligonucleotides [13], proteins [14, 15], and DNA fragments [16].
