The analysis of proteins under denaturing conditions is routinely performed with @entity214 - @entity2975 gel electrophoresis. The automated capabilities of CE, use of nongel sieving matrixes, and on-line optical detection by either ultraviolet (UV) absorption or laser-induced fluorescence (LF) promise to revolutionize this method. While direct on-line detection of proteins is possible as a result of their intrinsic ability to absorb light in the UV part of the spectrum (detection sensitivity comparable to Coomassie Blue staining of gels), @entity8020 provides more powerful detection but requires pre- or postcolumn fluorescence labeling of the proteins. The development of a protocol analogous to that used for double-stranded DNA analysis, where fluorescent intercalating dyes are simply included in the separation medium, would simplify size-based protein analysis immensely. This would avoid the complications associated with covalent modification of the proteins but still exploit the sensitivity of @entity8020 detection. We demonstrate that this is possible with CE and microchip detection by incorporating, into the run buffer, a fluorescent dye that interacts hydrophobically with protein- @entity214 complexes. Key to this is a dye that fluoresces significantly when bound to protein- @entity214 complexes but not when bound to @entity214 micelles. Comparison of electropherograms from CE-based denaturing protein analysis with UV and @entity8020 detection indicates that the presence of the fluor does not alter separation of the proteins. Moreover, comparison with electropherograms generated from microchip electrophoresis with @entity8020 detection shows that equivalent patterns can be obtained. Despite the unoptimized nature of this separation system, a dynamic labeling protocol that allows for @entity8020 detection for proteins is attractive and has the potential to circumvent the tedious labeling steps typically required.

Dynamic labeling during capillary or microchip electrophoresis for laser-induced fluorescence detection of protein- XXXX complexes without pre- or postcolumn labeling.

@entity2975 :: ('CHEBI:51135', 'Chemical') :: ['polyacrylamide'] @entity214 :: ('CHEBI:8984', 'Chemical') :: ['SDS'] @entity8020 :: ('3976', 'Gene') :: ['LIF']
@entity214 :: (CHEBI:8984,Chemical) :: ['SDS']
