Modified Deoxyoligonucleotides Stable to Exonuclease Degradation in Serum

Nucleic Acids Res. 1991 Feb 25;19(4):747-50. doi: 10.1093/nar/19.4.747.


Unmodified deoxyoligonucleotides are rapidly degraded in serum-containing medium. Utilizing internally labelled deoxyoligonucleotides the deoxyribonuclease profile for fetal calf serum and human serum was determined. It was found that the predominate nuclease activity in both systems was 3' exonuclease. Deoxyoligonucleotides are protected from exonuclease degradation in sera and cell media by simple terminal modifications that maintain high binding activity for the complementary DNA sequence.

MeSH terms

  • Base Sequence
  • Blood*
  • Chromatography, High Pressure Liquid
  • Electrophoresis, Polyacrylamide Gel
  • Exonucleases / chemistry*
  • Hot Temperature
  • Humans
  • Molecular Sequence Data
  • Nucleic Acid Denaturation
  • Oligonucleotides / chemistry*
  • Oxygen / chemistry*
  • Tumor Cells, Cultured


  • Oligonucleotides
  • Exonucleases
  • Oxygen