The Calbiotech CA-125 ELISA Kit is intended for the quantitative determination of the Cancer Antigen (CA) 125 concentration in human serum.
SUMMARY AND EXPLANATION
Cancer Antigen 125 (CA-125) is a surface antigen associated with epithelial ovarian cancer. In serum, CA-125 is associated with a high molecular weight glycoprotein. Published studies have indicated that elevated serum CA-125 levels can be found in individuals with serious endometroid, clear-cell and undifferentiated ovarian carcinoma. The serum CA-125 concentration is greater than 35 units per ml in 60% of women with ovarian cancer and >80% of patients with disseminated ovarian cancer. The serum CA-125 is elevated in 1% of normal healthy women, 3% of normal healthy women with benign ovarian diseases, 6% of patients with non-neoplastic conditions (including but not limited to first trimester pregnancy, menstruation, endometriosis, uterine fibrosis, acute salphingitis, hepatic diseases and inflammation of peritoneum, pericardium or pleura). Serial determinations of serum CA-125 as well as pelvic examination increase the test specificity. Serum CA-125 concentration may be useful in monitoring treatment and distinguishing between good response to treatment and progressive malignant disease with poor therapeutic response. To date, CA-125 is the most sensitive marker for residual epithelial ovarian cancer. CA-125 may also be elevated in patients with lung, cervical, fallopian tube, and uterine cancer and endometriosis.
PRINCIPLE OF THE TEST
The CA-125 ELISA test is based on the principle of a solid phase enzyme-linked immunosorbent assay.The assay system utilizes a monoclonal antibody directed against a distinct antigenic determinant on the intact CA-125 molecule is used for solid phase immobilization (on the microtiter wells). A rabbit anti-CA-125 antibody conjugated to horseradish peroxidase (HRPO) is in the antibody-enzyme conjugate solution. The test sample is allowed to react simultaneously with the two antibodies, resulting in the CA-125 molecules being sandwiched between the solid phase and enzyme-linked antibodies. After 90 minutes of incubation at 37°C, the wells are washed with water to remove unbound labeled antibodies. A solution of TMB Reagent is added and incubated for 20 minutes, resulting in the development of a blue color. The color development is stopped with the addition of Stop Solution changing the color to yellow. The concentration of CA-125 is directly proportional to the color intensity of the test sample. Absorbance is measured spectrophotometrically at 450 nm.