Description(s):
Prostatic acid phosphatase (PAP) is an enzyme expressed by prostate epithelium and pain-detecting spinal cord neurons. This protein is upregulated in men with prostate cancer, especially if it has metastasized. Furthermore, high levels of PAP may be found in other diseases such as Paget’s disease, sickle-cell disease, and multiple myeloma. There has been interest in using PAP as a biomarker for prostate cancer due to its potential role in prognosticating intermediate and high-risk cases.
Principle
The wells of the plate are coated with capture antibody specific to PAP. In this assay, the test sample initially reacts with the solid phase capture antibody, resulting in PAP 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 PAP. After washing away the unbound antibodies, Streptavidin-HRP conjugate is added to form a complex with the antibody-bound PAP. 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 PAP 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.
