Human Protein S ELISA Kit
Human Protein S ELISA Kit is designed for detection of human protein s in plasma and serum. This assay employs a quantitative competitive enzyme immunoassay technique that measures human protein s in less than 3 hours. A polyclonal antibody specific for human protein s has been pre-coated onto a 96-well microplate with removable strips. Protein S in standards and samples is competed by a biotinylated protein s sandwiched by the immobilized antibody and 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.
Protein S is a single-chain vitamin K-dependent plasma glycoprotein consisting of 635 amino acids with a molecular weight of about 70 kDa (1 - 3). It functions as a cofactor for the anticoagulant activated protein c to inhibit blood coagulation. In plasma, it is both in a free cofactor active form and in an inactive form complexed with C4b-binding protein (C4BP) (4). The complex acts as a bridge between coagulation and inflammation due to the involvement of C4BP in regulating complement activation. Hereditary protein s deficiency causes recurrent venous thrombosis (5). Acquired protein s deficiency is associated with nephrotic syndrome, disseminated intravascular coagulation, liver disease and the use of oral anticoagulants, leading to increased thrombotic risk (6).