Identification of two distinct rabbit antibodies directed against different antigenic components of avian brain

Two types of antibodies directed against biochemically different antigens have been found in antisera produced by hyperimmunizing rabbits with whole homogenates of chicken or quail brain. DEAE-cellulose column chromatography was used to separate the two antibodies which, based on differences in sedimentation rate and susceptibility to inactivation by 2-mercaptoethanol, were identified as belonging to the 7S and 19S classes respectively. Although both antibodies fix complement in the presence of whole brain homogenates, the 19S fraction reacts only with the chloroform—methanol extractable portion while the 7S fraction reacts only with the residue remaining after such extraction. It is concluded that the 19S and 7S antibodies are directed against lipid or lipoprotein and protein antigens respectively.