Description(s):
Epididymis Protein 4 (HE4) is a protein that is expressed in pulmonary epithelial cells and functions as a protease inhibitor. HE4 has been found to promote the proliferation and metastasis of cytotoxic lymphocytes. Additionally, this protein is known to be a biomarker for ovarian cancer. Its high sensitivity in detecting ovarian cancer in patients makes it a useful target in clinical tests.
Principle
The wells of the plate are coated with capture antibody specific to HE4. In this assay, the test sample initially reacts with the solid phase capture antibody, resulting in HE4 being bound to the well. The wells are then washed to remove unbound proteins, and biotin-linked antibodies are added to bind to the immobilized HE4. After washing away the unbound antibodies, Streptavidin-HRP conjugate is added to form a complex with the antibody-bound HE4. After incubation, the wells are washed to remove unbound Streptavidin-HRP conjugate. TMB substrate is then added and forms a blue color when the HRP-linked antibodies are detected. The reaction is then terminated with Stop Solution, which changes the color from blue to yellow. The HE4 concentration in each well is directly proportional to its color intensity and can be quantified by measuring its optical density at 450 nm (OD450) in a microplate reader.
