The antigen used for syphilis serological tests• Non-specific antigen- Cardiolipin(1) Isolated from the beef heart and named cardiolipin.(2) Referred to as the Wassermann antigen.(3) A kind of diphosphatidylglycerol lipid.(4) A hapten must be bound with syphilis antigens or other components to form a complete antigen and be antigenic to induce the formation of anti-cardiolipin antibodies.(5) Used for RPR and VDRL tests.a. To detect non-specific IgG or IgM (reagin)