Microplate Chemiluminescence Enzyme Immunoassay for the Determination of Carcinoembryonic Antigen in Human Serum

A highly sensitive, specific, simple, and rapid microplate chemiluminescence enzyme immunoassay (CLEIA) was developed for the determination of carcinoembryonic antigen (CEA) in human serum, which used luminol-H2O2 catalyzed by horseradish peroxidase (HRP) as the chemiluminescence system. Several physicochemical parameters such as the immunoreaction conditions, the dilution ratio of anti-CEA-HRP conjugate, and chemiluminescent time were studied and optimized. A sandwiched reaction was performed with incubation at room temperature for 1 h, followed by addition of 100 μl chemiluminescent substrate and measuring after 10 min incubation. The correlation coefficient of the proposed method was 0.9998. The detection limit was 0.57 μg l−1. The relative standard deviation (RSD) of interassay and intraassay coefficient of variation (CV) were both less than 10%. The average recoveries of three different spiked concentration samples were 107%, 93.3%, and 104%, respectively. The proposed method has been successfully applied to the determination of CEA in 40 human sera and showed a good correlation compared with the commercial CLIA kit with a correlative coefficient of 0.9115. This method has great potential in the fabrication of diagnostic kit and could be used in the clinical analysis of CEA in human serum.