The Eagle Biosciences Prekallikrein ELISA Assay Kit employs the sandwich enzyme immunoassay technique for the detection of Human Prekallikrein (total) in human plasma samples. Human Prekallikrein will bind to the capture antibody coated on the microtiter plate. After appropriate washing steps, anti-Human Prekallikrein primary antibody binds to the captured protein. Following a washing to remove unbound substances, secondary antibody conjugated to Horseradish Peroxidase (HRP) is added to each microplate well and incubated. After washing away any unbound antibody-enzyme reagent, a substrate solution (TMB) is added to the wells and color develops in proportion to the amount of Prekallikrein bound in the initial step. The color development is stopped by the addition of acid and the intensity of the color is measured at a wavelength of 450nm ±2nm. The concentration of Prekallikrein in the sample is then determined by comparing the O.D of samples to the standard curve. Sample Types: plasma. Range: 20 - 10000 ng/ml. Sensitivity: 0.018 μg/ml. Time: 1.5 hours ? Prekallikrein is the glycosylated single chain zymogen precursor of the plasma serine protease kallikrein. Plasma prekallikrein circulates with kininogen and is activated by Factor XIIa in the intrinsic coagulation pathway. Kallikrein activates plasminogen in fibrinolysis and cleaves kininogen in the bradykinin system of vasodilation. Prekallikrein deficiency is rare and causes increased activated partial thromboplastin time. Elevated plasma prekallikrein is associated with diabetes and cardiovascular disease.