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Divergent dispersion behavior of ss DNA fragments during microchip electrophoresis in p DMA and LPA entangled polymer networks
Author(s) -
Fredlake Christopher P.,
Hert Daniel G.,
Niedringhaus Thomas P.,
Lin Jennifer S.,
Barron Annelise E.
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.201100686
Subject(s) - dispersion (optics) , capillary electrophoresis , matrix (chemical analysis) , electric field , microfluidics , electrophoresis , dna , polymer , analytical chemistry (journal) , gel electrophoresis , materials science , polyacrylamide , chemistry , chromatography , nanotechnology , physics , optics , polymer chemistry , composite material , biochemistry , quantum mechanics
Resolution of DNA fragments separated by electrophoresis in polymer solutions (“matrices”) is determined by both the spacing between peaks and the width of the peaks. Prior research on the development of high‐performance separation matrices has been focused primarily on optimizing DNA mobility and matrix selectivity, and gave less attention to peak broadening. Quantitative data are rare for peak broadening in systems in which high electric field strengths are used (>150 V/cm), which is surprising since capillary and microchip‐based systems commonly run at these field strengths. Here, we report results for a study of band broadening behavior for ss DNA fragments on a glass microfluidic chip, for electric field strengths up to 320 V/cm. We compare dispersion coefficients obtained in a poly( N , N ‐dimethylacrylamide) (p DMA ) separation matrix that was developed for chip‐based DNA sequencing with a commercially available linear polyacrylamide ( LPA ) matrix commonly used in capillaries. Much larger DNA dispersion coefficients were measured in the LPA matrix as compared to the p DMA matrix, and the dependence of dispersion coefficient on DNA size and electric field strength were found to differ quite starkly in the two matrices. These observations lead us to propose that DNA migration mechanisms differ substantially in our custom p DMA matrix compared to the commercially available LPA matrix. We discuss the implications of these results in terms of developing optimal matrices for specific separation (microchip or capillary) platforms.