Chromogranin A ELISA

Enzyme immunoassay for the quantitative determination of human Chromogranin A in serum.

INTENDED USE: Enzyme immunoassay for the quantitative determination of Chromogranin A in serum. The determination of Chromogranin A helps in the detection of neuroendocrine tumors and is used to assess the course of the cancer treatment. The quantitative determination of Chromogranin A (CgA) follows the basic principles of the enzyme immunoassay. First, the Chromogranin A in the samples, controls and standards binds to CgA-specific antibodies fixed to a 96 wells microtiter plate. After incubation and following washing steps, a sandwich is formed by adding CgA antibodies conjugated to horseradish peroxidase. After incubation the wells are washed thoroughly and the complex bound to the solid phase is detected by using TMB as a substrate resulting in a colour reaction. The reaction is monitored at a wavelength of 450 nm. By means of a standard curve the CgA concentrations in the samples are determined. Manual processing of the ELISA is recommended. The use of automatic laboratory equipment is the responsibility of the user. This in-vitro diagnostic is for professional use only.

GENERAL INFORMATION: Chromogranin A (CgA) is an acid glycoprotein with 439 amino acids that is present in the secretory dense core granules of most neuroendocrine cells [1]. The chromogranin family consists of at least three different water-soluble acidic glycoproteins (CgA, CgB, and secretogranin II, sometimes called Chromogranin C). Upon stimulation, CgA and other peptide hormones and neuropeptides are released. CgA is also secreted from neuroendocrine-derived tumors. Neuroendocrine tumors (NETs), which originate from neuroendocrine cells, are found widely distributed throughout the body. The most common sites of NET are the lung, stomach, appendix, cecum, duodenum, pancreas, jejunum/ileum, colon and rectum. NET arising from the gastrointestinal tract are collectively known as gastroenteropancreatic neuroendocrine tumors (GEP-NET) and account for approximately 2/3 of incident NET. The annual incidence of NET is estimated as 2 – 5 cases per 100,000 population. CgA is widely expressed throughout the neuroendocrine system and serves as a general biomarker for a wide variety of neuroendocrine tumors. The determination of Chromogranin A helps in the detection of neuroendocrine tumors and is used to assess the course of cancer treatment. Therapeutic consequences should never be based on laboratory results alone, even if these results are assessed in accordance with the quality criteria of the method. Any laboratory result is only a part of the total clinical picture of the patient. Only in cases where the laboratory results are in an acceptable agreement with the overall clinical picture of the patient, it can be used for therapeutic consequences.

KIT CHARACTERISTICS:
- Method: ELISA
- Tests: 96
- Incubation Time / Conditions: 1 h, 1 h, 25 min (RT/shaker)
- Standard Range: 30 - 900 µg/l
- Sensitivity analytical: LoD: 1.4 µg/l
- Final Sample Volume: 50 µl
- Sample Type: serum
- Sample Pretreatment: 1+8 diluted
- Isotope / Substrate: TMB 450 nm
- Internal Controls: 2
- Regulatory Status: CE