Light Scattering and Viscosimetric Studies on DNA after the Photoreaction with Some Furocoumarins

1968 ◽  
Vol 23 (7) ◽  
pp. 943-945 ◽  
Author(s):  
F. Dall’Acqua ◽  
M. Terbojevich ◽  
F. Benvenuto
Keyword(s):  
Light Scattering ◽  
Double Bond ◽  
Scattering Measurements ◽  
Before And After ◽  
Pyrimidine Bases ◽  
Macromolecule Conformation ◽  
Dna Solutions

The light scattering measurements and the viscosimetric “i-assay” performed on native DNA solutions before and after irradiation at 3655 Å in the presence of furocoumarins show that the C4-cycloadditions of furocoumarins to the 5,6-double bond of the pyrimidine bases of DNA, which take place in the photoreactions, produce neither breakages of the polynucleotide chains nor relevant modifications of the macromolecule conformation.

Scattering Rings in Birefringent Porous Silicon

2003 ◽  
Vol 762 ◽  
Author(s):  
Claudio J. Oton ◽  
Zeno Gaburro ◽  
Mher Ghulinyan ◽  
Nicola Daldosso ◽  
Lucio Pancheri ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Light Scattering ◽  
Porous Silicon ◽  
Direct Measurement ◽  
Optical Anisotropy ◽  
Oblique Incidence ◽  
Laser Light ◽  
Anisotropic Scattering ◽  
Scattering Measurements

AbstractWe report the observation of strongly anisotropic scattering of laser light at oblique incidence on (100)-oriented porous silicon layers. We performed angle-resolved light scattering measurements and three concentric rings were observed. Modeling porous silicon by means of nanometric columnar air pores and an effective anisotropic uniaxial dielectric constant explains the observed phenomenon, and besides, the observation of the angle aperture of these rings allows a direct measurement of relative birefringence. We finally study the changes of optical anisotropy after different modifications of the structure.

A STUDY OF A WATER-SOLUBLE COMPLEX OF PRODIGIOSIN PRODUCED BY A STRAIN OF SERRATIA MARCESCENS

1962 ◽  
Vol 40 (1) ◽  
pp. 1019-1024 ◽  
Author(s):  
Seiichi Yoshida
Keyword(s):  
Molecular Weight ◽  
Light Scattering ◽  
Serratia Marcescens ◽  
Average Molecular Weight ◽  
Electrophoretic Analysis ◽  
Water Soluble ◽  
Soluble Complex ◽  
Ph Values ◽  
Scattering Measurements ◽  
Water Soluble Complex

A water-soluble pigment excreted from Serratia marcescens has been purified by precipitation with ammonium sulphate, dialysis, and ultracentrifugation at different pH values. The purified pigment showed a single band in the ultracentrifuge and by electrophoretic analysis at several pH values. An average molecular weight of 5 × 106 was calculated from light-scattering measurements. This pigment is composed of carbohydrate and protein combined with prodigiosin, and several properties of the complex are described.

Light scattering measurements on microemulsions: Estimation of droplet sizes

2006 ◽  
Vol 312 (1-2) ◽  
pp. 187-195 ◽  
Author(s):  
C. Goddeeris ◽  
F. Cuppo ◽  
H. Reynaers ◽  
W.G. Bouwman ◽  
G. Van den Mooter
Keyword(s):  
Light Scattering ◽  
Scattering Measurements ◽  
Droplet Sizes

Light Scattering and Flow Dichroism Studies on DNA After the Photoreaction with Psoralen

1972 ◽  
Vol 27 (2) ◽  
pp. 196-200 ◽  
Author(s):  
S. Marciani ◽  
M. Terbojevic ◽  
F. Dall’Acqua
Keyword(s):  
Heat Treatment ◽  
Molecular Weight ◽  
Light Scattering ◽  
Double Helix ◽  
Heat Denaturation ◽  
Scattering Measurements ◽  
Helix Structure ◽  
Double Helix Structure

Light scattering measurements performed on DNA after irradiation in the presence of psoralen clearly show that inter strand cross linkings are present in the macromolecule. In fact after heat denaturation and successive cooling irradiated macromolecule shows a molecular weight practically unchanged while a DNA sample after the same treatment shows a molecular weight half of the intact native DNA. Also the general conformation of irradiated DNA undergoes practically to no modifications after the same heat treatment while native DNA shows itself to have been strongly modified. Moreover, on the basis of flow dichroism determinations, DNA cross-linked by psoralen after heat denaturation showed to be able to restore its ordered double helix structure, during the successive cooling.

Sign in / Sign up

Export Citation Format

Share Document