ORGANIZATION OF NUCLEOLAR DNA IN RESTING LYMPHOCYTES AS REVEALED BY THE DIAMINOBENZIDINE TECHNIQUE

Nucleolar DNA organization in resting lymphocytes was studied with oxidized diaminobenzidine, which is a highly selective stain for nucleic acids at low pH. This technique, combined with enzymatic digestions, enables us to observe a gradual decondensation of a portion of the perinucleolar DNA until it becomes spread into the fibrillar RNP zone of the nucleolus. The presence and significance of these dispersed DNA structures within this fibrillar zone are discussed. It is concluded that the gradual decondensation of certain portions of the perinucleolar chromatin is a general feature of nucleolar organization. © 1979 Academic Press, Inc.