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Microfluidic Chips Controlled with Elastomeric Microvalve Arrays
Published on: October 1, 2007
Highly efficient dynamic modification of plastic microfluidic devices using proteins in microchip capillary
Nahoko Naruishi1, Yoshihide Tanaka, Tetsuji Higashi
1Human Stress Signal Research Center, HSS, National Institute of Advanced Industrial Science and Technology, AIST, 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577, Japan.
Journal of Chromatography. A
|July 25, 2006
Summary
New dynamic coating agents, including blocking proteins, effectively manipulate electroosmotic flow (EOF) in microchip electrophoresis. This simple method offers stable, reproducible control over EOF for various analytical separations.
Area of Science:
- Analytical Chemistry
- Microfluidics
- Separation Science
Background:
- Electroosmotic flow (EOF) is crucial for separations in microchip capillary electrophoresis (CE).
- Controlling EOF in poly(methylmethacrylate) (PMMA) microchips is essential for reproducible analytical results.
- Existing methods for EOF manipulation can be complex or require additives in the running buffer.
Purpose of the Study:
- To investigate novel dynamic coating agents for manipulating EOF in PMMA microchips.
- To evaluate the efficacy of blocking proteins (Block Ace, UltraBlock) and lysozyme as EOF modifiers.
- To demonstrate the simplicity, stability, and reproducibility of the proposed dynamic coating method.
Main Methods:
- Dynamic coating of PMMA microchannels using protein solutions (Block Ace, UltraBlock, lysozyme).
- Manipulation of EOF by adjusting buffer pH and protein charge.
- Electrophoretic separation of amino acids and biogenic amines derivatized with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F).
Main Results:
- EOF could be enhanced, suppressed, or reversed by varying buffer pH and protein charge.
- Block Ace and UltraBlock coatings demonstrated stability for at least five runs with low relative standard deviation (RSD < 4.3%).
- Coating procedures showed high reproducibility, with channel-to-channel RSD values for EOF < 5.0%.
Conclusions:
- Dynamic coating with blocking proteins offers a simple and effective strategy for EOF control in microchip CE.
- The method eliminates the need for coating agents in the running buffer, simplifying analysis.
- This technique holds significant potential for diverse applications in microchip CE separations.
