SpecificityThe PAI-1 ELISA is capable of quantitating PAI-1 in the active and latent forms as well as in complex with tPA and uPA. The assay has been tested for cross-reactivity by challenging with PAI-2, tPA, and Ovalbumin, which show no cross-reactivity at high-challenge doses. Also, the assay has been analyzed for parallel response of tumor samples over a range of concentrations and shows excellent agreement for replicate sample dilutions.
SensitivityThe PAI-1 ELISA will detect 0.10 ng/mL of PAI-1 in the sample tested. The signal of the 0.10 ng/mL Standard is greater than two times the zero (background) signal.
Intended UseHuman PAI-1 ELISA Kit allows for the in vitro quantitative determination of PAI-1 , concentrations in serum, Plasma , tissue homogenates and Cell culture supernates and Other biological fluids.
StorageFor 5-7days:Store the whole kit at 4℃
For a Long time :Store the Substrate at 4℃, other reagent should store at -20℃.
Product Categories/FamilyOncology; Research Assays; Assay Categories
Product Description specificalPrinciple of the assay: The PAI-1 ELISA measures all forms of human PAI-1. It is a sandwich-type immunoassay that utilizes a monoclonal antibody to human PAI-1 as the capture reagent. The Capture Antibody has been immobilized on the interior surface of microtiter plate wells. To perform the test, an appropriate volume of specimen is incubated in the coated well to allow binding of the antigen by the Capture Antibody. The immobilized antigen is then reacted with the PAI-1 detector rabbit antiserum. The amount of Detector Antibody bound to antigen is measured by binding it with a goat-anti-rabbit IgG-horseradish peroxidase (HRP) Conjugate. Color development by incubation with OPD (o-phenylenediamine) Substrate enables quantitation of captured PAI-1. The colored reaction product is quantitated by spectrophotometry and reflects the amount of PAI-1 protein in the sample. For instructions, see the Detailed Protocol and Evaluation of Results sections of this booklet.
Background: PAI-1 is a 50-kDa glycoprotein member of the serine protease inhibitor (SERPIN) superfamily and is the principal physiological inhibitor of both forms of plasminogen activators (PAs), uPA (urokinase-type plasminogen activator), and tPA (tissue-type plasminogen activator). It is secreted in an active form, which spontaneously converts to a latent form , but it can be stabilized in the active form by binding to the plasma protein vitronectin [2,3]. Both tumor cells and capillary endothelial cells express higher levels of PAI-1 than other cell types . It is hypothesized that high levels of PAI-1 serve to protect the tumor stroma from degradation by high amounts of secreted uPA [5,6]. High PAI-1 also may contribute to tumor-induced angiogenesis [7, 8]. Initial studies focused on PAI-1 levels in tumor lysates and cytosols. Since PAI-1 is an inhibitor, it was surprising that increased levels were detected in tumor tissue. For example, a study in 2002 determined PAI-1 to be a strong prognostic indicator in tumors of primary breast cancer patients . Tissue findings were then extended to plasma studies and similar results were seen. Specifically, elevated plasma levels of PAI-1 have been documented in research studies of colon cancer patients [10,11], and reports suggest that PAI-1 may be a potential marker for monitoring disease progression. Another study showed increased levels of PAI-1 above the normal cutoff in 24% of breast cancer plasmas, 30% of colon cancer plasmas, 40% of lung cancer plasmas, and 12% of prostate cancer plasmas . More recently, it was shown that metastatic breast cancer patients who had elevated pretreatment plasma PAI-1 had a shorter overall survival than metastatic breast cancer patients with normal levels of PAI-1 . In order to understand the potential clinical utility of measuring PAI-1 in plasma, additional studies are necessary. Plasma samples can be analyzed for PAI-1 levels using the PAI-1 ELISA. This assay detects all forms of human PAI-1. The availability of a quantitative, reproducible, standardized assay measuring PAI-1 in plasma allows researchers to examine the potential clinical value of measuring this circulating marker at any time during cancer. Although previous research on PAI-1 levels was conducted using tissue cytosols, plasma sample testing is more convenient and less invasive than tissue cytosol analysis and could provide investigators with the ability to measure this analyte in various cancer types.