The DRG CEA ELISA is an enzyme immunoassay for the quantitative in vitro diagnostic measurement of Carcinoembryonic Antigen (CEA) in serum.Carcinoemroyonic antigen (CEA) is a 200 kD glycoprotein. Cells that express CEA, both incorporate this glycoprotein into their cell membrane and release it into the blood. CEA is therefore detectable both on cells and in body liquids. The normal values are normally < 5 ng/mL Tumors that are associated with increased CEA values are: Colon carcinoma, stomach carcinoma, breast cancer, lung cancer, pancreatic cancer, gullet cancer. The most important role of CEA is in colon cancer, since the level of CEA correlates with the stage of the tumor.The DRG CEA ELISA Kit is a solid phase enzyme-linked immunosorbent assay (ELISA) based on the sandwich principle. The microtiter wells are coated with a monoclonal antibody directed towards a unique antigenic site of the CEA molecule. An aliquot of patient sample containing endogenous CEA is incubated in the coated well with enzyme conjugate, which is an anti-CEA antibody conjugated with horseradish peroxidase. After incubation the unbound conjugate is washed off. The amount of bound peroxidase conjugate is proportional to the concentration of CEA in the sample. Having added the substrate solution, the intensity of colour developed is proportional to the concentration of CEA in the patient sample.