Human Complement C4 ELISA Kit
Human complement C4 ELISA Kit is designed for detection of human complement C4 in plasma and serum. This assay employs a quantitative competitive enzyme immunoassay technique that measures human complement C4 in less than 3 hours. A polyclonal antibody specific for human complement C4 has been pre-coated onto a 96-well microplate with removable strips.Complement C4 in standards and samples is competed by a biotinylated complement C4 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.
Complement component 4 (C4) plays a key role in the activation of the classical complement pathway. C4 is synthesized as a single-chain precursor molecule (200 kDa) but processed to the three-chain disulphide-linked structure with alpha (93 kDa), beta (78 kDa), and gamma (33 kDa) chains prior to secretion (1 - 2). After activation by C1s, C4 is processed to C4a and C4b. C4a anaphylatoxin is a mediator of local inflammation and induces smooth muscle contraction (3). C4b, the major activation product, is an essential subunit of the C3 and C5 convertases of the classical complement pathway. C4 deficiency is associated with systemic lupus erythematosus (5). The C4b degradation product C4d is a marker for humoral rejection in allografts (6).