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High‐resolution electrophoretic separation and integrated‐waveguide excitation of fluorescent DNA molecules in a lab on a chip
Author(s) -
Dongre Chaitanya,
van Weerd Jasper,
Besselink Geert A. J.,
van Weeghel Rob,
Vazquez Rebeca Martinez,
Osellame Roberto,
Cerullo Giulio,
Cretich Marina,
Chiari Marcella,
Hoekstra Hugo J. W. M.,
Pollnau Markus
Publication year - 2010
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.201000126
Subject(s) - microfluidics , electrophoresis , capillary electrophoresis , waveguide , excitation , materials science , fluorescence , resolution (logic) , sizing , capillary action , chip , matrix (chemical analysis) , lab on a chip , laser , optoelectronics , analytical chemistry (journal) , optics , nanotechnology , chemistry , chromatography , physics , computer science , telecommunications , organic chemistry , quantum mechanics , artificial intelligence , composite material
By applying integrated‐waveguide laser excitation to an optofluidic chip, fluorescently labeled DNA molecules of 12 or 17 different sizes are separated by CE with high operating speed and low sample consumption of ∼600 pL. When detecting the fluorescence signals of migrating DNA molecules with a PMT, the LOD is as low as 2.1 pM. In the diagnostically relevant size range (∼150–1000 base‐pairs) the molecules are separated with reproducibly high sizing accuracy (>99%) and the plug broadening follows Poissonian statistics. Variation of the power dependence of migration time on base‐pair size – probably with temperature and condition of the sieving gel matrix – indicates that the capillary migration cannot be described by a simple physical law. Integrated‐waveguide excitation of a 12‐μm narrow microfluidic segment provides a spatio‐temporal resolution that would, in principle, allow for a 20‐fold better accuracy than the currently supported by state‐of‐the‐art electrophoretic separation in microchips, thereby demonstrating the potential of this integrated optical approach to fulfill the resolution demands of future electrophoretic microchips.