Miniaturised isotachophoresis of DNA

This paper presents the findings of a feasibility study investigating the behaviour of DNA under conditions of miniaturised isotachophoresis. An electrolyte system comprising a leading electrolyte of 5 mM perchloric acid at pH 6.0 and a terminating electrolyte of 10 mM gallic acid was devised and used to perform isotachophoresis of DNA containing samples on a miniaturised poly(methyl methacrylate) device. Under such conditions it was found that no separation of DNA fragments was observed with the substance migrating instead as a single isotachophoretic zone. Whilst such a result shows the method is unsuitable for analysis DNA it offers significant potential as a means of sample preparation for subsequent analysis using another method. This is because the single zone of DNA formed is preconcentrated to a constant concentration governed by the leading ion and is separated from all species with different effective electrophoretic mobilities.