FLUORESCENCE SPECTRAL CHARACTERISTICS OF NOVEL ASYMMETRIC MONOMETHINECYANINE DYES IN NUCLEIC-ACID SOLUTIONS

Six new asymmetric monomethine cyanine dyes have been synthesized and their fluorescence characteristics in the presence of nucleic acids st udied. The new dyes have no fluorescence of their own in mater solutio ns upon excitation at 480 nm but they become strongly fluorescent in t he presence of nucleic acids. The fluorescence maxima of the investiga ted dyes are found at 525-545 nm when bound to dsDNA and around 600 nm upon binding to RNA and ssDNA. Fluorescence quenching studies with in creasing concentrations of NaCl indicate that the cyanine dyes have a mixed (intercalating and groove binding) type of interaction with dsDN A. (C) 1997 Federation of European Biochemical Societies.