Single-step labeling of DNA using restriction endonucleases and T4 polynucleotide kinase

DNA restriction fragments can be end-labeled in a combined digestion and labeling reaction with restriction endonuclease plus T4 polynucleotide kinase, omitting a dephosphorylation step. Both pBR322 and phage lambda DNA digests are efficiently labeled in one step, one tube and one incubation.