Plasminogen Activator Inhibitor 1 (PAI-1) is a glycoprotein found in plasma that is implicated in the processes of angiogenesis, hemostasis, tumor metastasis, fibrionlysis, ovulation, embryonic development and inflammation (1). The elevation of PAI-1 has shown to correlate with the prognosis of many cancers including breast cancer (2,3,4). PAI-1 is activated by the glycoprotein vitronectin. Vitronectin binds to PAI-1 and modulates fibrinolysis and cell migration (5). This binding has proven to be an important inhibitor of the activated form of protein C (APC) (6).
Principle of the Assay:This is an ELISA for the quantitative analysis of PAI-1 levels in biological fluid. This test kit operates on the basis of sandwich ELISA where active PAI-1 complexes with uPA and is quantified with the use of an HRP-labeled secondary antibody.
The functional or active PAI-1 binds to the uPA coated on the well of the microtiter plate. The latent and complexed forms of PAI-1 will not bind and are discarded at a later washing step. Next, a PAI-1 primary antibody is added to the wells binding to the captured PAI-1 on the microtiter plate. HRP-conjugated secondary antibody is then added for detection of the active-PAI-1. Quantitative test results are obtained by the measure and comparison of the sample and standard absorbance readings.
Storage and Stability:May be stored at 4°C. For long-term storage, aliquot and store at 4°C. Do not freeze. Aliquots are stable for 6 months after receipt. For maximum recovery of product, centrifuge the original vial prior to removing the cap. Further dilutions can be made in assay buffer.
