The specificity of the reaction of antipurin-6-oyl sera with thermally denatured DNA has been studied by means of hapten inhibition techniques. The relative order of effectiveness of various haptens as inhibitors of the complement fixation reaction between DNA and antipurin-6-oyl serum was found to be comparable to their relative order of effectiveness as inhibitors of the precipitin reaction between purin-6-oyl-protein conjugates and antipurin-6-oyl serum. Antipurin-6-oyl antibody has been purified and has been shown to be capable of reacting with thermally denatured DNA. It is concluded that the reactivity of these purine-specific antisera with DNA is a property of antibody with specificity for the purin-6-oyl moiety.
In addition, the reaction between antipurinoyl sera and DNA has been demonstrated by the techniques of radioimmunoelectrophoresis and passive cutaneous anaphylaxis.