Reactmty of Antipu'rinoyl Serum with Dna

Rabbi ts immunized with purin-6-oyl-protein conjugates form antibodies with purine specificity. These antibodies are capable of fixing complement (C t) in the presence of thermally denatured deoxyribonucleic acid (DNA). This reaction was found to be specifically inhibited by purines and purine derivatives (1). Since the purines in D N A are linked to the deoxyribose-phosphate "backbone" a t the 9-position, while the antipurinoyl ant ibody was elicited in response to an antigen in which the purine was coupled via the 6-position, it was not clear whether the specific reaction with D N A was characteristic of the total antipurinoyl ant ibody in the antisera, or whether this reaction was typical of a relatively small proportion of the antibody. This report shows tha t the reactions of antipurinoyl sera with D N A and with purinoyl-protein antigens are similar in specificity. In addition, it contains a demonstrat ion of the reaction between antipurinoyl sera and thermally denatured D N A by the techniques of radioimmunoelectrophoresis (2, 3) and passive cutaneous anaphylaxis (4).