Occurence of nucleoside polyphosphates in rapidly labelled RNA preparations from radish seedlings (Raphanus sativus.).

Preparations of rapidly labelled RNA are usually heavily contaminated by rapidly labelled low molecular weight components. This contaminating fraction mainly contains nucleoside triphosphates, as previously reported, but also nucleoside tetra, penta and hexaphosphates. These highly phosphorylated nucleosides are, according to recent literature, likely candidates for an important regulatory role in the coordination of a variety of biochemical reactions. This is the first demonstration of their occurence in higher plants and a method is presented to separate them from other usual nucleotides.