Location of ribosomal DNA in the human chromosome complement.

Hybridization of (3)H-labeled ribosomal RNA to human chromosomes on slides resulted in specific labeling of the satellite regions of chromosomes 13, 14, 15, 21, and 22, with an over-all efficiency of about 5%. Differences between D and G chromosomes, and between associated and unassociated satellites, were not significant. Labeling of all other parts of the preparations was nonspecific, and increased in the order: extrachromosomal regions < chromosome arms < centric regions.