End-Group Labeling of Nucleic Acids by Enzymatic Phosphorylation

End-group analysis has proved to be a valuable technique for determining the homogeneity, molecular weight, and amino acid sequence of proteins (Sanger, 1952). End-group analysis of nucleic acids can provide similar information about these macromolecules. Although a number of techniques for end-group analysis of nucleic acids are now available, their usefulness has been limited. First, successful application of the technique depends upon the availability of homogeneous nucleic acid preparations; second, the method employed must be sensitive and quantitative; and third, the procedure used for analysis must not introduce extraneous end-groups. These considerations become increasingly important in the study of naturally occurring nucleic acids of high molecular weight.