Elimination of basic gaps at high pH values in 2-DE
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Updated: Jun 19, 2026

Capillary Electrophoresis-based Hydrogen/Deuterium Exchange for Conformational Characterization of Proteins with Top-down Mass Spectrometry
Published on: June 8, 2021
Lena Kask1, Kjell Larsson, Bengt Bjellqvist
1GE Healthcare Bio-Sciences AB, Uppsala, Sweden. lena.kask@ge.com
Abstract:
The appearance of gaps, vertical lanes lacking protein spots at the cathodic end of 2-D maps generated with wide range IPG-strips exceeding a pH value of 9, is shown to depend on the electro-osmotic transport of water into the IPG-strip. Substitution of urea solution with water is demonstrated to increase the hydrolysis rate of polyacrylamide in IPG-strips explaining the gap formation. The use of 8 M urea or thiourea/urea solutions in the electrode wick enables overnight focusing without the appearance of gaps.
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