Microplate chemiluminescence enzyme immunoassay for the quantitative evaluation of carbohydrate antigen 72-4 in human serum

• Published in: Chinese science bulletin Vol. 53; no. 19; pp. 2958 - 2963
• Main Authors: Jin, Hui, Wang, Xu, Xin, TianBing, Gao, Peng, Lin, Jin-Ming, Liang, ShuXuan
• Format: Journal Article
• Language: English
• Published: Heidelberg SP Science in China Press 01.10.2008
• Subjects: Chemistry/Food Science; Earth Sciences; Engineering; Humanities and Social Sciences; Life Sciences; multidisciplinary; Physics; Science; Science (multidisciplinary); 免疫检测; 化学发光; 肿瘤标记; tumor marker; carbohydrate antigen 72-4; human serum; chemiluminescence enzyme immunoassay
• ISSN: 1001-6538; 2095-9273; 1861-9541; 2095-9281
• DOI: 10.1007/s11434-008-0428-9

A highly sensitive and specific microplate chemiluminescence enzyme immunoassay （CLEIA） was developed for the quantitative evaluation of carbohydrate antigen 72-4 （CA72-4） in human serum, using luminol-H2O2 catalyzed by horseradish peroxidase （HRP） as the chemiluminescence system. The simple and quick determination was accomplished through a sandwich reaction mode. Several physicochemical parameters of the immunoreaction, including incubation conditions, antibody coating conditions, dilution ratio of anti-CA72-4-HRP conjugate, and chemiluminescence reaction time, were studied and optimized. The proposed method exhibited a linear range of 0-200 U/mL with correlation coefficient and detection limit of 0.9995 and 0.18 U/mL, respectively. The inter-assay and intra-assay coefficients of variation （CV） were both less than 10%. The average recovery of two clinical sera with low and high concentration CA72-4 was 99.3% and 98.7%, respectively. Normal tumor markers, including AFP, CEA, CA24-2, CA19-9 and CA15-3, did not cross-react with each other. The method＇s stability was evaluated by assessing its analytical performance after storing the immunoreagents at 4℃ and 37℃ for 7 days. Little difference was found, indicating satisfactory stability of the method. The present method has been successfully applied to the detection of CA72-4 human serum, and showed a good correlation with the commercially available ELISA kit （r^2=0.9383）. This method showed great potential in the fabrication of diagnostic kit for CA72-4, and could be well used in diagnosis of cancer in clinical practice.