Imaging devices, electrophoretic

Electrostatic and electrical double-layer interactions also create new opportunities in science and technology. We have already seen an example of this in a vignette in Chapter 1 on electrophoretic imaging devices, and another, on electrophotography, is described in the next... 

The EPID concept can be combined with other developments in imaging technology to produce optical devices such as light valves and x-ray imagers. The accompanying illustration shows an example of an electrophoretic x-ray imager. 

The most successful applications of CE-LIF detection have been in the analysis of carbohydrates and nucleic acids. Carbohydrates can be derivatized with agents such as aminopyrene trisulfonic acid, which introduces a fiuorophore and also confers electrophoretic mobility to the analyte. Double-stranded nucleic acids can be detected using intercalating dyes and by covalent attachment of nucleotides carrying fluorophores. The fluorescently labeled primers or chain terminating nucleotides which are widely used in automated slab gel-based DNA sequencers are also used in capillary-based sequencers. In one multicapillary sequencer, a novel sheath flow system is used for LIF excitation of separated bands with imaging of emitted fluorescence on a charge-coupled device (CCD) detector. 

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