Beta-HCG ELISA Assay Kit

Additional Information

Assay Background

Human chorionic gonadotropin (HCG) is a glycoprotein hormone secreted in pregnancy, that is made by the embryo soon after conception and later by the syncytiotrophoblast (part of the placenta). Its role is to prevent the disintegration of the corpus luteum of the ovary and thereby maintain progesterone production that is critical for a pregnancy in humans. HCG may have additional functions, for instance it is thought that it affects the immune tolerance of the pregnancy.

Pregnancy tests measure the levels of HCG in the blood or urine to indicate the presence or absence of an implanted embryo. In particular, pregnancy tests employ an antibody that is specific to the β-subunit of HCG (β-HCG). This is important so that tests do not make false positives by confusing HCG with LH and FSH. β-HCG is also secreted by some cancers including teratomas and choriocarcinomas. But, elevated levels cannot prove the presence of a tumor, and low levels do not rule it out.

Assay Principle

Eagle Biosciences β-HCG ELISA Assay Kit for β -HCG is based on the simultaneous capture of HCG by a monoclonal antibody immobilized on the microplate and directed against the β -HCG fraction, and another monoclonal antibody conjugated with peroxidase horseradish (HRP) and directed against the fraction α -HCG.

After the incubation, the bound/free separation is performed by a simple solid-phase washing.  The enzyme HRP in the bound-fraction reacts with the Substrate (H2O2) and the TMB Substrate and develops a blue color that changes into yellow when the Stop Solution (H2SO4) is added. The color intensity is proportional to the β-HCG concentration in the sample. The β-HCG concentration in the sample is calculated based on a calibration curve.