ABSTRACT
Affinity techniques have become important methods for isolation of specific RNA sequences. Chromatography on columns of oligo(dT)-cellulose or poly(U)-agarose separates most mRNAs containing 3’-terminal poly(A) segments from total cellular RNA. Immobilized DNA forms specific hybrids with complementary RNA. This provides a general method for the isolation of RNA having sequence homology with DNA from any given source. Procedures have been developed for isolation and purification of polynucleotide fragments deriving from the terminals of large RNA. The method depends on the selective periodate oxidation of the 2’,3’-diol groups of the terminal fragment after cleavage of the RNA, and the specific binding of the fragment to AE-cellulose. Bacillus emersonii zoospores and germlings were assayed for the presence of poly RNA by the poly(U)-glass-fiber filter binding technique and oligo(dT)-cellulose chromatography. Synaptosomal RNA of rat brain was labeled in vivo by intracranial injection of tritiated uridine. Young rats have a greater amount of brain RNA which contains poly (A) than do adult animals.
