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On‐line coupling of sample preconcentration by LVSEP with gel electrophoretic separation on T‐channel chips
Author(s) -
Kitagawa Fumihiko,
Kinami Saeko,
Takegawa Yuuki,
Nukatsuka Isoshi,
Sueyoshi Kenji,
Kawai Takayuki,
Otsuka Koji
Publication year - 2017
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.201600184
Subject(s) - chromatography , analytical chemistry (journal) , repeatability , electrophoresis , chemistry , stacking , channel (broadcasting) , organic chemistry , electrical engineering , engineering
To achieve an on‐line coupling of the sample preconcentration by a large‐volume sample stacking with an electroosmotic flow pump (LVSEP) with microchip gel electrophoresis (MCGE), a sample solution, a background solution for LVSEP and a sieving solution for MCGE were loaded in a T‐form channel and three reservoirs on PDMS microchips. By utilizing the difference in the flow resistance of the two channels, a low‐viscosity sample and a viscous polymer solution were easily introduced into the LVSEP and MCGE channels, respectively. Fluorescence imaging of the sequential LVSEP‐MCGE processes clearly demonstrated that a faster stacking of anionic fluorescein and successive introduction into the MCGE channel can be carried out on the T‐channel chip. To evaluate the preconcentration performance, a conventional MCZE analysis of fluorescein on the cross‐channel chip was compared with LVSEP‐MCGE on the short T‐channel chip, and as a result that the value of sensitive enhancement factor (SEF) was estimated to be 370. The repeatability of the peak height was good with the RSD value of 3.2%, indicating the robustness of the enrichment performance. In the successive LVSEP‐MCGE analysis of φX174/HaeIII digest, the DNA fragments were well enriched to a sharp peak in the LVSEP channel, and they were separated in the MCGE channel, whose electropherogram was well‐resembled with that in the conventional MCGE. The values of SEF for the DNA fragments were calculated to be ranging from 74 to 108. Thus, the successive LVSEP‐MCGE analysis was effective for both preconcentrating and separating DNA fragments.