title: Study on the resonance light scattering spectrum of berberine-cetyltrimethylammonium bromide system and the determination of nucleic acids at nanogram levels.
abstract: The interaction of berberine with nucleic acid in the presence of cetyltrimethylammonium bromide (CTMAB) in aqueous solution has been studied by spectrophotometry and resonance light scattering (RLS) spectroscopy. At pH 7.30, the RLS signals of berberine were greatly enhanced by nucleic acid in the region of 300-600 nm characterized by four peaks at 324.0, 386.5, 416.5 and 465.0 nm. The binding properties were examined by using a Scatchard plot based on the measurement of enhanced RLS data at 416.5 nm. Under optimum conditions, the increase of RLS intensity of this system at 416.5 nm is proportional to the concentration of nucleic acid. The linear range is 7.5 x 10(-9)-7.5 x 10(-5) g ml(-1) for calf thymus DNA, 7.5 x 10(-9)-2.5 x 10(-5) g ml(-1) for herring sperm DNA, and 5.0 x 10(-9)-2.5 x 10(-5) g ml(-1) for yeast RNA. The detection limits (S/N = 3) are 2.1 ng ml(-1) for calf thymus DNA, 6.5 ng ml(-1) for herring sperm DNA and 3.5 ng ml(-1) for yeast RNA, respectively. Three synthetic samples were analyzed satisfactorily.
authors.affiliation: Key Lab for Colloid and Interface Chemistry of Education Ministry, Department of Chemistry, Shandong University, Jinan, China.
authors.forename: Rutao
authors.initials: R
authors.lastname: Liu
authors.forename: Jinghe
authors.initials: J
authors.lastname: Yang
authors.forename: Xia
authors.initials: X
authors.lastname: Wu
authors.forename: Changxia
authors.initials: C
authors.lastname: Sun
mesh_terms: D000818:Animals; D001599:Berberine / Q000032:analysis* / Q000737:chemistry; D002138:Calibration; D002417:Cattle; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000032:analysis*; D004247:DNA / Q000032:analysis; D004305:Dose-Response Relationship, Drug; D005399:Fishes; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008027:Light; D008956:Models, Chemical; D012542:Scattering, Radiation; D013053:Spectrophotometry / Q000379:methods*; D013501:Surface-Active Agents / Q000494:pharmacology; D013997:Time Factors
chemical_list: D002593:Cetrimonium Compounds; D013501:Surface-Active Agents; D001599:Berberine; D004247:DNA; D000077286:Cetrimonium