Noncompetitive immunoassay for follicle-stimulating hormone in human serum using capillary electrophoresis with chemiluminescence detection.

A noncompetitive immunoassay based on capillary electrophoresis (CE) with chemiluminescence (CL) detection has been developed for the determination of follicle-stimulating hormone (FSH) in human serum. The work involved the development of separation and CL conditions allowing for routine analysis of serum samples. In this study, horseradish peroxidase (HRP)-labeled monoclonal anti-FSH can catalyze the luminol-hydrogen peroxide reaction. The determined FSH can react with an excessive amount of HRP-labeled anti-FSH. Within 15 min, free enzyme conjugate and immune complex could be separated in alkaline borate buffer by a high voltage of 15 kV. To improve the sensitivity, a series of measures was adopted, including the choice of sodium tetraphenylboron as a new CL enhancer, with a unique design in the detect window. Under optimal conditions, the calibration curve for FSH was established in the concentration range of 1-150 IU/L and the detection limit was 0.08 IU/L. Compared with enzyme-linked immunosorbent assay (ELISA), this method decreased the detection limit by about 25-fold, and it has been successfully employed on determination of the FSH in human serum.