Chemiluminescence Immunoassay for Simultaneous Detection of α-Fetoprotein and Carcinoembryonic Antigen

A novel flow-through chemiluminescent (CL) immunoassay was designed for the simultaneous detection of alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA). Two transparent microtubes immobilized with monoclonal antibodies were set in a mobile flow cell. Based on a sandwich immunoassay format, two mixtures of the sample antigens and corresponding horseradish peroxidase (HRP) labeled antibodies were introduced into the channels for on-line incubation. After the injection of luminol and H2O2 solution, different CL signals from the two transparent microtubes were sequentially detected by moving the mobile flow cell. The effects on the chemiluminescence detection, such as the immunological reaction time, the concentrations of luminol and H2O2, and the pH value of the buffer solution, were carried out. Under the optimal experimental conditions, AFP and CEA could be detected in the linear ranges of 1.25 - 50 mu g/L and 1.25 - 40.0 mu g/L with detection limits of 1.06 and 1.0 mu g/L, respectively. The actual samples of human serum was analyzed with satisfactory results.