A biosensor for determination of the circulating biomarker CA125/MUC16 by Surface Plasmon Resonance Imaging.

CA125/MUC16 is an ovarian tumor cell marker widely used as a biomarker in epithelial ovarian carcinoma. CA125/MUC16 is also used for evaluation of the ROMA (Risk of Ovarian Malignancy Algorithm) value. In this work, a Surface Plasmon Resonance Imaging (SPRI) biosensor for circulating CA125/MUC16 has been developed. The anti-MUC16 antibody was attached to a gold chip via a cysteamine linker. The EDS/NHS protocol was used for the covalent attachment of the antibody. The developed biosensor is specific for CA125/MUC16, and exhibits good recovery and acceptable precision. Its linear response range (2.2-150 U/ml) is well suited to determination of the marker in the blood serum of a healthy control group and, after appropriate dilution, of patients with ovarian cancer. CA125/MUC16 was determined in two series of real samples: blood serum from patients with ovarian cancer and endometrial cysts. The method was validated by parallel determination of the samples using the chemiluminescent Architect i2000 method.