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pH Change of buffer solution in a microcapillary chip and its suppression
Author(s) -
Oki Akio,
Takamura Yuzuru,
Ito Yoshitaka,
Horiike Yasuhiro
Publication year - 2002
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/1522-2683(200209)23:17<2860::aid-elps2860>3.0.co;2-j
Subject(s) - capillary electrophoresis , chemistry , capillary action , electrophoresis , electrolysis , buffer (optical fiber) , chromatography , electro osmosis , salt (chemistry) , chip , analytical chemistry (journal) , materials science , electrode , electrolyte , electrical engineering , composite material , engineering , telecommunications , computer science
During the electrophoresis separation of B‐ and T‐cells from lymphocytes employing a microcapillary chip, they were found to become inactive in the reservoir after a short time. This was caused by the buffer solution becoming alkaline due to electrolysis. This was considered to take place in chips with small reservoir volumes. The pH change was confirmed by the ISFET (ion‐sensitive field effect transistor) embedded in the chip. To suppress the pH change, two methods were studied. One is the insertion of a salt bridge just in front of and behind the capillary, thus introducing an electric potential but stopping flow of the acid and alkaline solutions into the capillary. The other is neutralization of the alkaline solution in the reservoir by injecting the acid solution produced in another capillary with the same structure by employing an electroosmotic flow (EOF) pump. Both methods achieved no pH change during electrophoresis measurements in the microcapillary.