Development and Clinical Application of a Chemiluminescence Immunoassay for Determination of Carbohydrate Antigen 125

To develop a chemiluminescence immunoassay (CLIA) kit for quantitative determination of tumor marker carbohydrate antigen 125 (CA125) and evaluate its value of clinical application, CLIA for quantitative determination of CA125 was established by using micro-plates coated with antibody to CA125, combined with HRP conjugated anti-CA125 antibody, as well as luminol chemiluminescence substrate system. The national reference control sera were used for evaluation of specificity, sensitivity, stability and accuracy of the established CLIA. CA125 levels in sera from 350 clinical samples were parallel determined by the established methods and reference kits produced by the Siemens. The results show that the efficiency of the CLIA reagents met the requirements of national reference standard. The intra coefficient variations (CV) were between 2.8%~3.6% and inter CV 3.7%. The kit showed good stability after being kept at 37˚C for 3d. The established CLIA showed good correlation with the reference kits (negative concordance rate, positive concordance rate and overall concordance rate were 99.5%, 99.3% and 99.4% respectively, and a correlation coefficient r = 0.9897. High degree of agreement was observed with a Kappa value of 0.99). A rapid, specific, sensitive and stable CLIA kit for quantitative determination of CA125 was successfully established and that will be fit for widely application in clinical laboratory.