title: DNA-spermine and DNA-lipid aggregate formation visualized by fluorescence correlation spectroscopy.
abstract: BACKGROUND
  Fluorescence correlation spectroscopy (FCS) can be used for the determination of diffusion coefficients of single molecules. Since diffusion coefficients are correlated with size and shape of the labeled species, FCS provides information on conformational changes in plasmids aggregates.
  
  
  METHODS
  A 10-kbp plasmid stained with PicoGreen was condensed by spermine or liposomes formulated from cationic lipid and egg phosphatidylcholine.
  
  
  RESULTS
  The diffusion coefficient of DNA increases from 1.0 x 10(-12) m2/s to 3.2 x 10(-12) m2/s by the addition of spermine, whereas the addition of cationic liposomes leads to complexes characterized by diffusion coefficients with values ranging from 1.7 to 1.9 x 10(-12) m2/s.
  
  
  CONCLUSIONS
  FCS experiments allow determining the diffusion coefficients of DNA-containing aggregates which provide information regarding the topology and homogeneity of the aggregate.
authors.affiliation: J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic. tek@ozi.ar.wroc.pl
authors.forename: Teresa
authors.initials: T
authors.lastname: Kral
authors.forename: Marek
authors.initials: M
authors.lastname: Langner
authors.forename: Martin
authors.initials: M
authors.lastname: Hof
mesh_terms: D004247:DNA / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry; D006801:Humans; D008055:Lipids / Q000737:chemistry*; D009930:Organic Chemicals / Q000737:chemistry; D010957:Plasmids / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013096:Spermine / Q000737:chemistry*; D013194:Staining and Labeling
chemical_list: D005456:Fluorescent Dyes; D008055:Lipids; D009930:Organic Chemicals; C099476:PicoGreen; D013096:Spermine; D004247:DNA