On-chip capillary electrophoresis for alkaline phosphatase testing

We fabricated an on-chip capillary electrophoresis device for blood analysis. An on-chip capillary electrophoresis device was photolithographically fabricated on a glass chip. Alkaline phosphatase (ALP) was employed as a sample enzyme. Small amounts of enzyme in the mixture of other proteins were detected with the electrophoretically mediated microanalysis (EMMA) method. Fluorescein diphosphate was used as fluorogenic substrate. The detection of ALP activity was achieved with laser-induced fluorescence monitoring fluorescein that was produced in enzyme reaction in capillary. Several methods to reduce the adhesion of protein are also discussed.