Following G-quartet formation by UV-spectroscopy

FEBS Lett. 1998 Sep 11;435(1):74-8. doi: 10.1016/s0014-5793(98)01043-6.


Oligodeoxynucleotides which include stretches of guanines form a well-known tetrameric structure. We show that the recording of reversible absorbance changes at 295 nm allows to precisely monitor intramolecular guanine (G)-quartet formation and dissociation. Accurate Tm and thermodynamic values could be easily extracted from the data, whereas classical recordings at 260 nm led to a much larger uncertainty and in extreme cases, to completely inaccurate measurements. This inverted denaturation profile was observed for all G-quartet-forming oligonucleotides studied so far. This technique is very useful in all cases where intramolecular or intermolecular quadruplex formation is suspected.

MeSH terms

  • DNA / chemistry*
  • Dimerization
  • G-Quadruplexes
  • Guanine / chemistry*
  • HIV-1
  • Nucleic Acid Conformation*
  • Oligodeoxyribonucleotides / chemistry
  • Oligonucleotides, Antisense / chemistry
  • RNA, Viral / chemistry
  • Spectrophotometry, Ultraviolet
  • Thermodynamics


  • Oligodeoxyribonucleotides
  • Oligonucleotides, Antisense
  • RNA, Viral
  • Guanine
  • DNA