title: Radiolabelling of DNA/polypeptide complexes in isolated bulk DNA and in residual nuclear matrix DNA by nick-translation.
abstract: Conditions are described that allow 32P-radiolabelling and detection of tight complexes between DNA and polypeptides by nick-translation. Prolonged nick-translation of purified bulk DNA results in radiolabelled complexes migrating on SDS-polyacrylamide gels with apparent molecular weights of 68 kd and 54 kd respectively. Residual nuclear matrix DNA which is not accessible to DNase I on the nuclear level becomes accessible to radiolabelling by nick-translation on the nuclear matrix level. In this case the in situ radiolabelled complexes migrate on SDS-polyacrylamide gels with apparent molecular weights of 68 kd and 100 kd. The DNA/polypeptide complexes are stable during treatments with SDS, beta-mercapto ethanol and alkali which points to covalent bonds between the polypeptides and DNA strands.
mesh_terms: D002467:Cell Nucleus / Q000648:ultrastructure*; D004247:DNA / Q000096:biosynthesis / Q000378:metabolism*; D004256:DNA Polymerase I / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D003850:Deoxyribonuclease I / Q000378:metabolism; D008970:Molecular Weight
chemical_list: D004268:DNA-Binding Proteins; D004247:DNA; D004256:DNA Polymerase I; D003850:Deoxyribonuclease I