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'Ethidium Bromide' in keywords
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1984 (1)
1981 (1)
1980 (1)
1Author    Ruth Marx, Detlef DoeneckeRequires cookie*
 Title    Binding of Polylysine and Ethidium Bromide to Nucleosomal DNA: Comparison of Biochemical and Electron Microscopical Results  
 Abstract    Ethidium bromide and polylysine interact with nucleosomal D NA and lead to changes o f biochemical properties and to morphological changes as to the distance between the two core particles of a nucleosome dimer. With increasing polylysine concentration, the buoyant density of nucleosomes decreases and the accessibility of the nucleosomal DNA to micrococcal nuclease is lowered. Electron microscopy of polylysine treated nucleosome dimers reveals a shortening of the intemucleosomal distance as compared with controls. Treatment of nucleosomes with ethidium bromide leads to an enhanced accessibility of the nucleosomal DNA to micrococcal nuclease. Electron microscopy reveals an increase in length of the DNA connecting the two nucleosome cores in the presence o f the dye. Both the binding of polylysine and the treatment with ethidium bromide apparently do not affect the histone arrangement within the nucleosome core as suggested by chemical cross-linking o f histones and DNA with formaldehyde, and no obvious morphological changes of the nucleosome cores can be observed. 
  Reference    Z. Naturforsch. 36c, 149—156 (1981); received September 1 1980 
  Published    1981 
  Keywords    Nucleosomes, Polylysine, Ethidium Bromide, Biochemistry, Morphology 
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 TEI-XML for    default:Reihe_C/36/ZNC-1981-36c-0149.pdf 
 Identifier    ZNC-1981-36c-0149 
 Volume    36 
2Author    D., K. Tempel, A. Goette, I. SchmeroldRequires cookie*
 Title    Unterschiede zwischen Milz-und Thymuszellen der Ratte in der Wirkung von Ethidiumbromid auf die unprogrammierte DNA-Synthese (DNA-Reparatursynthese) und die Nucleoidsedimentation  
 Abstract    ifferences between R at S p len ic and T h y m ic C e lls w ith R esp ec t to th e E ffects o f Ethidium Brom ide on the U nsheduled D N A S y n th e sis (D N A Repair S yn th esis) and the N u cleo id S e d im e n ta tio n To get further insight into the causes o f differences betw een rat splenic and thym ic cells with regard to D N A repair synthesis, scheduled (SD S) and unscheduled (U D S) D N A synthesis as well as nucleoid sedimentation o f the cells were investigated under the influence o f ethidium brom ide (EB, 1 -1 0 0 0 ng/m l). -At concentrations o f ^ 2 5 |ig /m l, EB inhibited SD S o f both cell species and UD S o f thymic cells; much higher additions o f the drug (> 2 0 0 |ig /m l) were needed to diminish UDS o f splenic cells, lower EB-concentrations (2 5 -175 n g /m l) stim ulating the U D S o f the splenic cell preparation. -The sedimentation rate o f splenic and thym ic cell nucleoids within neutral sucrose gradients had a biphasic dependence on the EB-concentrations. As com pared to thymic cells however, preincubation o f splenic cells w ith 5 0 -2 5 0 ng EB/m l resulted in a significant greater (1 5 -3 0 percent) sedim entation distance. — The results suggest that a relation­ ship exists between the stimulation o f U D S and the ability o f cells to establish a greater D N A compactness in the presence o f EB. 
  Reference    Z. Naturforsch. 39c, 600—605 (1984); received October 31/M arch 22 1984 
  Published    1984 
  Keywords    Ethidium Bromide, D N A Repair Synthesis, Nucleoid Sedim entation, Splenocytes, Thym ocytes 
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 TEI-XML for    default:Reihe_C/39/ZNC-1984-39c-0600.pdf 
 Identifier    ZNC-1984-39c-0600 
 Volume    39 
3Author    Jürgen Pauluhn, Annem Arie, N. Aujok, H. Erbert, W. Zim, Erm AnnRequires cookie*
 Title    Über die quantitative fluorometrische Bestimmung von DNA mit Ethidiumbromid in der Zelle und die Konstanz der Quantenausbeute des Ethidium-DNA-Komplexes im biologischen Milieu On the Q uantitative Fluorom etric D eterm ination of Cellular DNA by Ethidium Bromide and the Constancy o f the Quantum Yield of the Ethidium -D N A -Com plex in the Biological Environment  
 Abstract    The fluorescent staining o f fixed A 9 cells (m ouse fibroblasts) with ethidium brom ide E has been investigated qualitatively and quantitatively. E is bound to D N A , R N A and protein. After enzymatic R N A digestion and staining at pH = 4.0 the dyestuff is bound to D N A specifically. The formed E -D N A -com plex is stoichiom etric if D N A will be saturated by high dye concentra­ tion, CF = 1.0 x 10~2 M. The stoichiom etric factor n = 0.21 was determined from Scatchard bind­ ing isotherms and by spectrophotometric titration. The binding o f E to D N A and R N A has been investigated by binding isotherms. E is bound to D N A by intercalation and by ionic interaction. It is bound to R N A by ionic interaction only. The ionically bound dyestuff can be replaced by salts like LiCl from D N A and RNA. Only inter­ calated E remains. The com petitive salt effect can be used to avoid the enzym atic R N A digestion in the specific staining o f D N A . W ithin the cell the E-D N A -com plex fluoresces strongly. U sing a microspectrophotom eter we determined the fluorescence intensity J and the extinction E in cell sections o f q = 1 |a2 area. The fluorescence was excited in the m inimum o f the absorbance o f the E -D N A -com plex at = 365 nm. The extinction E 2 was measured in the short wavelength band at X2 = 260 nm. Under these conditions we received a linear relation J = J (E ?) up to high extinctions E 2. The quantum yield Q o f the E -D N A -com plex is nearly constant and independent o f the biological environment. Q is also unaltered by LiCl. W ithin the lim its o f error intercalated and ionic bound dye have the same quantum yield. Under the conditions o f stoichiom etric staining the am ount o f E -D N A -complex and therefore D N A in the cell can be determined by J. The extinction coefficient e2 = 45200 M-1 cm -1 o f the E -D N A -com plex at 260 nm was calcu­ lated from the concentration dependence o f the absorbance spectra using the law o f mass action. By e2 the am ount o f D N A in the cell is accessible from J. According to our measurements with A 9 cells the superficial density o f D N A has the order o f m agnitude £>n = m ^ /q = 101 nmol cm -2, the amount raN o f D N A per section q = 1 jj.2, mN = 10_l fmol, and the D N A concentration in the cell nucleus CN = 10-1 M. The ray pass and diagram o f electronics o f the used m icrospectrophotom eter are described. 
  Reference    Z. Naturforsch. 35c, 585—5 (1980); eingegangen am 14. Januar/21. April 1980 
  Published    1980 
  Keywords    D N A -determ ination, Ethidium Bromide, M ouse Fibroblasts, Specific Fluorescent Staining, Quantum Y ield, M icrospectrophotometer 
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 TEI-XML for    default:Reihe_C/35/ZNC-1980-35c-0585.pdf 
 Identifier    ZNC-1980-35c-0585 
 Volume    35