Performance of electrokinetic supercharging for high‐sensitivity detection of DNA fragments in chip gel electrophoresis

Abstract

Chip gel electrophoresis was explored for high-sensitivity detection of DNA by combining electrokinetic injection with transient isotachophoresis preconcentration (here named electrokinetic supercharging (EKS)). Low concentrations (0.2 mg/L) of DNA sample could be detected without fluorescence labeling using a conventional UV detector (at 260 nm). On a single-channel microchip, identification of PCR product was performed by exploiting both external and internal calibration methods. The deviation between the two calibration methods was about 3.6%, and the identified DNA fragment size matched with the predicted size of the template DNA. On the cross microchip the EKS preconcentration has also been achieved when changing the injection reservoir differing from the one used previously. The procedure was computer-simulated and the influence of the voltage applied to two-side reservoirs on sample preconcentration and dilution was also discussed.

Electrokinetic supercharging for highly efficient peptide preconcentration in capillary zone electrophoresis

“…For example Quirino and Terabe [20] have demonstrated that SEFs as high as several hundreds of thousands are reachable if FESI is used under sweeping condition. Also, Hirokawa and co-workers [21][22][23] have introduced few years ago the electrokinetic supercharging (EKS) methodology. In EKS, analytes are introduced into the separation capillary with an electrokinetic injection under conditions that are suitable for isotachophoretic stacking.…”

“…In EKS, analytes are introduced into the separation capillary with an electrokinetic injection under conditions that are suitable for isotachophoretic stacking. So far, EKS has been applied to rare-earth chlorides [21], DNA fragments [23], and proteins denaturated by SDS [22].…”

Capillary electrophoresis based on nucleic acid detection for diagnosing human infectious disease

“…The combination of these two fields requires researchers knowledgeable in both subjects, but many scientists lack such a comprehensive background. The relatively low sensitivity of CE analysis is the second limitation in the field of DNA analysis [136][137][138][139][140]. The double bond formed by the base group in DNA has a low UV-visible absorption, and a normal UV detector has a low sensitivity.…”

Unconventional detection methods for microfluidic devices

“…The instrument was utilized in testing the applicability of transforming affinity CE (ACE) techniques to microchip format [50], in the rapid separation of antimicrobial metabolites with high efficiency [51], and in chiral separations of pharmaceuticals by CD EKC [52,53]. The same system was employed in developing a method to test for nitrogen monoxide metabolites in biological fluids [54], along with a single-step quantitation of DNA [55], and chip gel electrophoresis method for high-sensitivity DNA detection [56], as well as a monosaccharide derivative separation [57].…”