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Effect of buffer flow on DNA separation in a microfabricated electrophoresis system
Author(s) -
Chen Zheng,
Burns Mark A.
Publication year - 2005
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.200500579
Subject(s) - buffer (optical fiber) , resolution (logic) , electrophoresis , buffer solution , analytical chemistry (journal) , microfluidics , chemistry , separation (statistics) , tris , chromatography , electrode , flow (mathematics) , materials science , nanotechnology , electrical engineering , mechanics , computer science , biochemistry , physics , artificial intelligence , machine learning , engineering
An adequate buffer reservoir is one essential component of an electrophoresis system, providing current carrying ions and maintaining constant pH. In a microfabricated DNA separation system with on‐chip electrodes, the amount of buffer used is limited by the design of the device; the buffer continuity can be easily disturbed by the production of bubbles. Continuously flowing 1×Tris‐borate‐EDTA (TBE) buffer over the electrodes at the cathodic end solves both problems. This flow increases the resolution for ssDNA primer separations (21 and 25 bases) to a maximum value of 1.4 within a distance of 1.2 cm, about four times higher than that without flow. Similar improvement has been achieved for dsDNA separation (20 bp ladder; BioRad) at a distance of only 0.4 cm, giving baseline resolution for bands from 20 to 240 bp. We have also investigated the effect of buffer concentration on resolution, and no similar improvement can be obtained by merely increasing the buffer concentration without flow.