The ribosenucleic acid content of isolated cell nuclei.

A m ethod is described for the estim ation, by furfural form ation, of small am ounts of ribosenucleic acid (RNA) in the presence of large am ounts of deoxyribosenucleic acid. Evidence is produced to show th a t the Schm idt & T hannhauser m ethod does no t give a satisfactory separation of the two types of nucleic acids. The m ethod has been applied to the estim ation of the R N A conten t of nuclei isolated from a num ber of different types of cell, and the values reported . I t is concluded th a t the nuclei as isolated contain small am ounts of RNA, b u t the possibility of adsorption of cytoplasm ic RN A by the nuclei during the isolation procedure cannot be excluded. No correlation was found betw een the RNA content of the isolated nuclei and the prom inence of the ir nucleolar systems.