Human Complement C4 (Active)

The Antibodies.com Human Complement C4 (Active) protein is supplied as a 100 µg liquid preparation used in in vitro complement pathway research. This active complement component plays a central role in the classical and lectin activation cascades, where proteolytic cleavage generates the C4a anaphylatoxin and the C4b fragment that anchors the C3 convertase (C4b2a) on target surfaces. Investigators apply this reagent in ELISA, Western blot, and hemolytic complement assays to study immune complex deposition, complement-mediated lysis, and disease states including systemic lupus erythematosus, C4 glomerulopathy, and autoimmune hemolysis where C4 deficiency or dysfunction is implicated. The unconjugated protein is provided in a vial and should be stored at -80 °C in single-use aliquots to preserve functional activity, with limited freeze-thaw cycles and short-term handling kept on ice.