Anti-C4S antibodies are protein reagents that detect specific antigens. The C4S antigen is another term for the human protein complement C4A (Rodgers blood group), encoded by the C4A gene. The protein is reported to be a non-enzymatic component of C3 and C5 convertases and thus essential for the propagation of the classical complement pathway. Canonically, it has an amino acid length of 1744 residues and a mass of 192.8 kilodaltons. It is a secreted protein and it is expressed in the placenta. Other alias names for C4S include C4, C4A2, and C4A3. Western Blot is a widely used application for the C4S antibodies listed below. In addition, ELISA is also a common application.