Online preconcentration by transient isotachophoresis in linear polymer on a poly(methyl methacrylate) microchip for separation of human serum albumin immunoassay mixtures.
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.
Mohamadi
Mohamad Reza
MR
Department of Applied Chemistry, Graduate School of Engineering, MEXT Innovative Research Center for Preventive Medical Engineering, and Plasma Nanotechnology Research Center, Nagoya University, Nagoya 464-8603, Japan. rezam@mail.apchem.nagoya-u.ac.jp
Kaji
Noritada
N
Tokeshi
Manabu
M
Baba
Yoshinobu
Y
D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex / Q000302:isolation & purification; D046209:Electrophoresis, Microchip / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D011108:Polymers; D019904:Polymethyl Methacrylate; D012709:Serum Albumin / Q000276:immunology / Q000302:isolation & purification*
D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D011108:Polymers; D012709:Serum Albumin; D019904:Polymethyl Methacrylate