[Detection of tissue-specific antigenic determinants of chromatin]

Rabbit antibodies against rat liver and thymus are obtained. IgG isolated from antithymus sera interact with homologous chromatin but do not interact with chromatin from hepatocytes. Antiliver IgG interact with chromatin from both organs: however, their pretreatment with thymocyte chromatin results in antibodies which interact only with liver chromatin. Thus, chromatin from liver and thymus contains both common and tissue-specific antigenic determinants. Immunization with thymocyte chromatin induces antibody synthesis only (or predominantly) against tissue-specific antigenic determinants. Upon immunization with liver chromatin the antibodies against tissue-specific antigenes and antigenes common for different organs are formed.