title: Specificity of cyanine dye L-21 aggregation in solutions with nucleic acids.
abstract: Optical spectroscopy experiments were used to study the features of cyanine dye 3,3'-dimethyl-9-(2-thienyl)-thiacarbocyanine iodide (L-21) aggregation in binary solutions DMF:Tris-HCl buffer (pH = 8) containing nucleic acids (DNA or RNA). The appearance of absorption and luminescence bands associated with J-aggregates and dimers that are formed within the minor groove of DNA has been observed. The model of L-21 J-aggregate structure is proposed. It has been found that dimers are the building blocks of L-21 J-aggregates. Disorientation in dimers caused by the minor groove curvature is reason of observation of Davydov splitting in absorption spectrum of L-21 J-aggregates. In the solution containing DNA the absorption and luminescence bands of L-21 J-aggregates exhibit the specific properties that allows the dye L-21 to be used as a fluorescent probe for DNA detection.
authors.affiliation: Institute for Scintillation Materials, STC Institute for Single Crystals, NAS of Ukraine, 60 Lenin Ave., 61001 Kharkov, Ukraine.
authors.forename: G Ya
authors.initials: GY
authors.lastname: Guralchuk
authors.forename: A V
authors.initials: AV
authors.lastname: Sorokin
authors.forename: I K
authors.initials: IK
authors.lastname: Katrunov
authors.forename: S L
authors.initials: SL
authors.lastname: Yefimova
authors.forename: A N
authors.initials: AN
authors.lastname: Lebedenko
authors.forename: Yu V
authors.initials: YV
authors.lastname: Malyukin
authors.forename: S M
authors.initials: SM
authors.lastname: Yarmoluk
mesh_terms: D000818:Animals; D002232:Carbocyanines / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry*; D004247:DNA / Q000737:chemistry; D066298:In Vitro Techniques; D046911:Macromolecular Substances; D008958:Models, Molecular; D015394:Molecular Structure; D009690:Nucleic Acid Conformation; D009696:Nucleic Acids / Q000737:chemistry*; D012313:RNA / Q000737:chemistry; D012996:Solutions; D013050:Spectrometry, Fluorescence; D013053:Spectrophotometry
chemical_list: D002232:Carbocyanines; D004396:Coloring Agents; D046911:Macromolecular Substances; D009696:Nucleic Acids; D012996:Solutions; D012313:RNA; D004247:DNA