Introduction Urokinase-type plasminogen activator (uPA) is a highly restricted serine protease that converts the zymogen plasminogen to active plasmin, a broad-spectrum serine proteinase capable of degrading most of the major protein components of the extracellular matrix. Binding of uPA to its receptor and subsequent uPA mediated pericellular proteolysis are involved in many process including cell migration and tissue remodeling in angiogenesis, atherogenesis, tumor cell metastasis, and ovulation (1, 2). High level of uPA is a poor prognostic marker for aggressive breast cancer, aggressive prostate cancer, bladder cancer and gastric cancer (3, 4, 5).
Principal of the Assay The AssayMax Human Urokinase (uPA) ELISA kit is designed for detection of human uPA in plasma, serum, tissue, saliva, milk, urine and cell culture supernatants. This assay employs a quantitative sandwich enzyme immunoassay technique that measures urokinase in less than 4 hours. A polyclonal antibody specific for uPA has been pre-coated onto a microplate. Urokinase in standards and samples is sandwiched by the immobilized antibody and a biotinylated polyclonal antibody specific for uPA, which is recognized by a streptavidin-peroxidase conjugate. All unbound material is then washed away and a peroxidase enzyme substrate is added. The color development is stopped and the intensity of the color is measured.