Further studies on the effect of some anti-coagulants upon sero-diagnostic tests for syphilis. II. Heparin, thymol-fluoride, isotonic oxalate, and concentrated citrate solution.

Ample evidence is available that body fluids other than serum contain antibodies (Coleman and Appleman, 1953; Kanter and Appleton, 1940; Klauder and Kolmer, 1921). Occasionally (Biro, 1947) these fluids reveal antibodies more frequently and sooner after infection of the bone marrow in syphilis. Plasma also has an antibody content (Addis, 1912; Cowie, 1909; Gurd, 1912), although some anti-coagulants interfere with the measurement of syphilitic reagin. However, upon the removal of the fibrinogen, some anticoagulants have no appreciable effect upon the serologic tests. Blood treated with potassium oxalate in optimal concentration can, therefore, be used as well as serum in these tests. The effects of the treatment of blood on the serodiagnostic tests for syphilis using the following anti-coagulants were studied: heparin, thymolsodium fluoride mixture, an isotonic potassium and ammonium oxalate mixture, and a concentrated sodium citrate solution. It was observed that clotted blood often resists haemolysis of the erythrocytes by bacterial lysis, enzymatic action, or physical forces, considerably longer than will a sample of the same blood drawn at the same time and treated with potassium oxalate salts sufficient to prevent coagulation. Potassium oxalate, although not added to the blood-taking tubes with sterile technique, will usually be sterile upon bacterial culture, and it is doubtful if the salt itself introduces microorganisms into the blood.