The binding of ethidium bromide with DNA: interaction with single- and double-stranded structures

Exp Mol Med. 2003 Dec 31;35(6):527-33. doi: 10.1038/emm.2003.68.

Abstract

The pH-induced helix-coil transition of DNA and its complexes with EtBr is carried out at acidic pH in a wide interval of change of concentration ratio of EtBr/DNA. The binding isotherms of EtBr on double and single-stranded DNA at pH = 7.0 and pH = 3.0 (t = 25(o)C) are obtained by absorption and fluorimetric methods. Binding constants (K) and number of bases (n), corresponding to one binding site were determined. Non fluorescent "strong" complex with ds-DNA at pH = 7.0 and t = 25(o)C as well as "strong" and "weak" complexes with ss-DNA at pH = 3.0 and t = 25(o)C are revealed.

MeSH terms

  • Animals
  • Cattle
  • DNA / chemistry*
  • DNA / metabolism*
  • DNA, Single-Stranded / chemistry*
  • DNA, Single-Stranded / metabolism*
  • Ethidium / analogs & derivatives*
  • Ethidium / chemistry
  • Ethidium / metabolism*
  • Hydrogen-Ion Concentration
  • Nucleic Acid Conformation*
  • Spectrometry, Fluorescence

Substances

  • DNA, Single-Stranded
  • 3,8-diamino-6-phenyl-phenanthridine
  • DNA
  • Ethidium