Fingerprinting nonradioactive ribonucleic acid with the aid of polynucleotide phosphorylase

Abstract
We describe a method for obtaining radioactive fingerprints from non-radioactive ribonucleic acid. Fragments derived by Tl ribonuclease digestion of RNA are dephosphorylated with bacterial alkaline phosphatase. When these fragments are used as primers for the reaction of primer dependent poly-nucleotide phosphorylase with [α-32P]GDP in the presence of Tl ribonuclease the 3′-hydroxyl group of each fragment becomes phosphorylated. The degree of phosphorylation is reasonably uniform. The method has been applied to Tl ribonuclease digests of Eecherichia coli ; the oligonucleotides were further analyzed by spleen phosphodiesterase digestion. In a similar manner fingerprints of pancreatic ribonuclease digests of RNA can be obtained, when [α-32P]UDP, polynucleotide phosphorylase and pancreatic ribonuclease are used.