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A semipermanent coating for preventing protein adsorption at physiological p H in kinetic capillary electrophoresis
Author(s) -
de Jong Stephanie,
Epelbaum Nicolas,
Liyanage Ruchi,
Krylov Sergey N.
Publication year - 2012
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.201200153
Subject(s) - coating , adsorption , protein adsorption , capillary action , chemistry , capillary electrophoresis , chromatography , chemical engineering , biophysics , materials science , organic chemistry , composite material , engineering , biology
Protein adsorption to the inner capillary wall hinders the use of kinetic capillary electrophoresis ( KCE ) when studying noncovalent protein–ligand interactions. Permanent and dynamic capillary coatings have been previously reported to alleviate much of the problems associated with protein adsorption. The characteristic limitations associated with permanent and dynamic coatings motivated us to look at a third type of coating – semipermanent. Here, we demonstrate that a semipermanent capillary coating, designed by L ucy and co‐workers, comprised of dioctadecyldimethylammonium bromide ( DODAB ) and polyoxyethylene ( POE ) stearate, greatly reduces protein adsorption at physiological p H – a necessary requirement for KCE . The coating (i) does not inhibit protein– DNA complex formation, (ii) prevents the adsorption of the analytes, and (iii) supports an electoosmotic flow required for many applications of KCE . The coating was tested in three physiological buffers using a well‐known DNA aptamer and four proteins that severely bind to bare silica capillaries as standards. For every protein, a condition was found under which the semipermanent coating effectively suppresses protein adhesion. While no coating can completely prevent the adsorption of all proteins, our findings suggest that the DODAB/POE stearate coating can have a broad impact on CE at large, as it prevents the absorption of several well studied, highly adhesive proteins at physiological p H .