Human Chromogranin A ELISA Kit

Background

The EDI™ Human Chromogranin A Chemiluminescence Immunoassay (CLIA) kit is designed, developed, and produced for the quantitative measurement of human CgA level in serum samples. The assay utilizes a two-site “sandwich” technique with two antibodies that bind to different epitopes of CgA. Assay calibrators, controls, or patient serum samples are added directly to a reaction vessel together with streptavidin coated magnetic particles and biotinylated anti-CgA polyclonal antibody. After an incubation period, a wash step is introduced and an acridinium ester conjugated anti-CgA monoclonal antibody is added to each reaction vessel. The magnetic particles capture the biotin antibody as well as an immuno complex in the form of “magnetic particles–biotin CgA antibody–CgA–acridinium ester CgA antibody”. Materials bound to the solid beads are held in a magnetic field while unbound materials are washed away. Then, trigger solutions are added to the reaction vessel and light emission is measured with the ECL100 or ECL25 analyzer. The relative light units (RLU) are proportional to the concentration of a CgA in the sample. The amount of analyte in the sample is determined from a built-in multi-point calibration curve and reported in serum CgA concentration.

Product Summary

Chromogranin A is a 49 kDa acidic protein that consists of 439 amino acids encoded on chromosome 14. Chromogranin A has been identified in a number of normal and neoplastic endocrine tissues. It is demonstrated that an elevated level of circulating chromogranin A is a marker for tumors of neuroendocrine origin. However, the most significant clinical use of chromogranin A is related to the diagnostic procedure in patients with pheochromocytoma. The following is a short summary of the potential usages of chromogranin A. ​​​​​​​

1. A very sensitive (83%) and highly specific (96%) marker in the evaluation of actual or suspected pheochromocytoma. Drugs commonly employed in the diagnosis or treatment of pheochromocytoma have little effect on plasma chromogranin A levels, which is a great advantage over the measurement of catecholamines. 
2. To ascertain the source of a tumor. A high chromogranin A level indicates that the tumor arises from neuroendocrine tissues.
3. Endocrine tumors that do produce their specific hormones, for example, calcitonin negative but chromogranin A positive C-cell carcinoma; zero-cell carcinoma; beta-cell carcinoma; parathyroid carcinoma.

For research use only. Not for use in diagnostics procedures.