Capillary Array Isoelectric Focusing With Laser Induced Fluorescence Detection: Milli-pH Unit Resolution and Yoctomole Mass Detection Limits in a 32 Channel System

摘要

We report a multiplexed capillary electrophoresis system employing an array of 32 capillaries with a micromachined sheath flow cuvette as the detection chamber. The sample streams were simultaneously excited with a 473 nm laser beam, and the fluorescence emission was imaged on a CCD camera with a pair of doublet achromat lens. The instrument produced mass detection limits of 380 ± 120 yoctomoles for fluorescein in zone electrophoresis. Capillary isoelectric focusing of fluorescent standards produced peaks with an average width of 0.0029 ± 0.0008 pH. Capillary coating stability limits the reproducibility of the analysis.