Nick translation of DNA immobilized on nylon membranes

Nick translation of DNA bound to nylon membranes is described. Phage lambda DNA was digested with restriction endonuclease HindIII. The fragments were separated by agarose electrophoresis and electrophoretically transferred to Zeta-Probe nylon membranes. After being air-dried, the areas with DNA fragments attached were cut out and subjected to nick translation. The labeled fragments, removed from the membranes by a single wash step, can be used as specific hybridization probes. Currently used methods require time-consuming electroelution and often additional purification procedures if a specific DNA fragment, separated by gel electrophoresis, is to be labeled by nick translation. With the procedure described it is possible to label many DNA fragments in parallel in a time- and cost-saving manner.