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Issue 6, 2005
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Microchannel protein separation by electric field gradient focusing

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A microchannel device is presented which separates and focuses charged proteins based on electric field gradient focusing. Separation is achieved by setting a constant electroosmotic flow velocity against step changes in electrophoretic velocity. Where these two velocities are balanced for a given analyte, the analyte focuses at that point because it is driven to it from all points within the channel. We demonstrate the separation and focusing of a binary mixture of bovine serum albumin and phycoerythrin. The device is constructed of intersecting microchannels in poly(dimethylsiloxane) (PDMS) inlaid with hollow dialysis fibers. The device uses no exotic chemicals such as antibodies or synthetic ampholytes, but operates instead by purely physical means involving the independent manipulation of electrophoretic and electroosmotic velocities. One important difference between this apparatus and most other devices designed for field-gradient focusing is the injection of current at discrete intersections in the channel rather than continuously along the length of a membrane-bound separation channel.

Graphical abstract: Microchannel protein separation by electric field gradient focusing

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Publication details

The article was received on 31 Jan 2005, accepted on 24 Mar 2005 and first published on 15 Apr 2005

Article type: Paper
DOI: 10.1039/B501538C
Citation: Lab Chip, 2005,5, 587-597
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    Microchannel protein separation by electric field gradient focusing

    D. N. Petsev, G. P. Lopez, C. F. Ivory and S. S. Sibbett, Lab Chip, 2005, 5, 587
    DOI: 10.1039/B501538C

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