Calbiotech Carcinoembryonic Antigen (CEA) ELISA

SUMMARY AND EXPLANATION 
Carcinoembryonic antigen (CEA), a 180 kD intercellular adhesion molecule expressed in high concentrations in the fetus but normally not found in adult serum because the synthesis of this protein ceases after birth. However reappear in a high concentration in the sera of patients with colorectal (57%), gastric (41%), hepatocellular (45%), pancreatic (59%) and biliary (59%) carcinoma. The serum concentration of CEA can also be elevated in benign diseases of the colorectum (inflammatory bowel disease 17%), stomach (chronic gastritis and peptic ulcer 14%), liver (cirrhosis and hepatitis 17%) and pancreas (21%). Elevated levels of CEA have also been observed in patients with inflammatory nonmalignant diseases like pulmonary emphysema, alcoholic cirrhosis, pancreatitis and in heavy smokers. In contrast to cancer these elevations are transitory. The serum levels drop back into the normal range within a few weeks. The primary use of CEA is to monitor patients after surgery for recurrent colorectal carcinoma. Serum CEA has sensitivity between 60% and 95% in detecting recurrences prior to clinical detection and a leadtime between 2 and 10 months (positive predictive value 65%; negative predictive value 70%). False- positive results are usually below 10.0 ng/ml.

PRINCIPLE OF THE TEST 
The CBI CEA is a solid phase sandwich ELISA method. The samples, and anti-CEA-HRP/Biotin conjugate are added to the wells coated with Streptavidin. CEA in the patient’s sample forms a sandwich between two specific antibodies to CEA. Unbound protein and HRP conjugate are washed off by wash buffer. Upon the addition of the substrate, the intensity of color is proportional to the concentration of CEA in the samples. A standard curve is prepared relating color intensity to the concentration of the CEA.

STORAGE AND STABILITY 
1. Store the kit at 2 - 8°C. 
2. Keep microwells sealed in a dry bag with desiccants. 
3. The reagents are stable until the expiration of the kit. 
4. Do not expose test reagents to heat, sun, or strong light.