Online preconcentration by transient isotachophoresis in linear polymer on a poly(methyl methacrylate) microchip for separation of human serum albumin immunoassay mixtures

Mohamad Reza Mohamadi, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba

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Online preconcentration of human serum albumin (HSA) and its immunocomplex with a monoclonal antibody by on-chip transient isotachophoresis is reported. An 800-fold signal enhancement was achieved following the preconcentration on standard cross-channel microchips made of poly (methyl methacrylate). Sample injection, preconcentration, and separation were done continuously and controlled solely by a sequential voltage switching program. The preconcentration was followed by on-chip nondenaturing gel electrophoresis in methylcellulose solution. The method was applied to microchip electrophoresis immunoassay of HSA. Baseline separation of HSA and its immunocomplex was achieved in 25 s in the first 1 cm of the microchannel. In a direct immunoassay, the minimum detectable concentration of fluorescent labeled HSA by laser-induced fluorescence detection was 7.5 pM.

Original languageEnglish
Pages (from-to)3667-3672
Number of pages6
JournalAnalytical Chemistry
Issue number10
Publication statusPublished - May 15 2007
Externally publishedYes


All Science Journal Classification (ASJC) codes

  • Analytical Chemistry

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