Resumo

BERTOLOTTO, J. A et al. Study of electric linear dichroism of sonicated and fractioned DNA through gel chromatography. An. AFA [online]. 2017, vol.28, n.1, pp.4-9. ISSN 0327-358X.

This work studies the dependence of reduced electric linear dichroism (RELD) of DNA samples as a function to the applied electric field. To do so, a DNA solution is subjected to sonication, which results in a sample whose molecular size range varies, approximately, between 100 and 1000 base pairs. In order to obtain more monodisperse fractions, the sample is fractionated using the gel chromatography method, obtaining various DNA fractions which are useful for the analysis by means of electrooptical techniques. These fractions are characterized using gel electrophoresis, so as to obtain the distribution of chain lengths and their average for each fraction. The RELD experimental results are fitted by means of a theoretical model of flexible curved rod with electric polarizability which saturates with the applied electric field, where it is taken into account not only the longitudinal electrical polarizability but also the transversal one. The results of this study are similar to the ones obtained by other authors using DNA fragmentation by restriction enzymes. The advantage of the fractionation technique used resides in the obtention of samples of larger volume to apply electrooptical techniques.

Palavras-chave : DNA; Electric linear dichroism.

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