Inhibition of ribonuclease contamination in preparations of T4 RNA ligase, polynucleotide kinase, and bacterial alkaline phosphatase with bentonite.

Commercial preparations of the enzymes used in the analysis of RNA primary structure (bacterial alkaline phosphatase, polynucleotide kinase, and RNA ligase) are virtually always more or less contaminated with RNases. This leads to degradation of initial RNAs in the course of labeling and formation of a set of spurious labeled fragments. We have shown that bentonite present in the incubation medium in a concentration of 0.04% selectively inhibits the contaminating RNases, not affecting the activities of bacterial alkaline phosphatase, polynucleotide kinase, and RNA ligase.