Cytochemistry of RNA in metaphase chromosomes of human PHA-blasts

RNA which is resistant in situ to ribonuclease in solutions of high ionic strength was demonstrated in interphase nuclei and metaphase chromosomes of human PHA-blasts. Since the synthesis of this RNase-resistant RNA is not affected by actinomycin D it is likely that it is of a non-ribosomal type. The resistance to ribonuclease is confirmed in part by the formation of RNA-protein complexes. Two features are characteristic of the localization of this type of RNA within the chromosome: (1) its localization in the telomeric regions; (2) its symmetrical distribution in sister chromatids.