Exceeding 20 000-fold concentration of protein by the on-line isotachophoresis concentration in poly(methyl methacrylate) microchip

In this research, a simple on-line microchip gel electrophoresis with ITP was applied for the concentration and separation of BSA and its immunoassay complex with mAb in a single cross form PMMA microchip. We investigated the ITP concentration effect in PMMA MCE using combination of leading electrolytes, terminating electrolytes and other factors. We realized an ITP-based concentration and separation of BSA and its immunoassay complexes in standard cross-channel microchip gel electrophoresis, which exceeded 2000-fold concentration of BSA immunocomplex using Tris-H₃PO₄ as a leading electrolyte and Tris-γ-amino butyric acid as a terminating electrolyte. In addition, we also realized concentration of BSA sample in water, which was more than 20 000-fold and was the result of the concentration effect from combining ITP and the sample stacking techniques.