Anti-SAP antibodies are used in antigen-specific immunodetection in biological samples. The target SAP is a known alias name of the protein amyloid P component, serum, encoded by the APCS gene in humans. This 223-amino acid residue protein is known to be involved in innate immune responses and the regulation of cell differentiation, among other biological processes. The protein is secreted and features N-glycosylated post-translational modifications. It is reported to be expressed in the testis.