Precipitating antibodies to DNA induced by heat-denatured DNA-albumin conjugates in the rabbit.

(1) Antibodies reactive with purified DNA in the complement fixation system and induced by active immunization of rabbits with methylated bovine serum albumin—DNA aggregate (MBSA—DNA) have been previously described. The present study demonstrates their reactivity in the quantitative and double diffusion preciptin systems. In these systems they have shown preferential reactivity with heat denatured DNA and great cross-reactivity with denatured DNA from various sources. (2) Methylated rabbit serum albumin—DNA aggregate (MRSA—DNA) is an effective immunizing antigen resulting in the production of antibodies similar to those produced by MBSA—DNA. (3) The precipitating antibodies in this system are 19S immunoglobulins and appear to be identical to the complement fixing antibodies. (4) The precipitin reaction is not significantly inhibited by mono-nucleotides.