Preparation of (beta-32P)ribonucleoside-5'-triposphates using permeable cells of Escherichia coli

A rapid method for the preparation of β-³²P]ribonucleoside-5′-triphosphates is described. The method involves the incubation of a ribonucleoside triphosphate with ³²P_i and E. coli cells made permeable to nucleotides. The labeled triphosphates can be isolated by preparative thin layer chromatography on poly(ethylene)imine cellulose plates. Labeled GTP, CTP, and UTP obtained by this method are more than 99% pure β-³²P]compounds. Labeled ATP contains about equal amounts of label in the β- and γ-phosphate position. Pure β-³²P]ATP can be obtained from this preparation by exchanging the γ-³²P against unlabeled P_i and reisolating the labeled ATP by charcoal adsorption and elution.