Spectrofluorometric measurement of the binding of ethidium to superhelical DNA from cell nuclei.

@article{Cook1978SpectrofluorometricMO,
  title={Spectrofluorometric measurement of the binding of ethidium to superhelical DNA from cell nuclei.},
  author={Peter R. Cook and I. A. Brazell},
  journal={European journal of biochemistry},
  year={1978},
  volume={84 2},
  pages={465-77}
}
Structures retaining many of the morphological features of nuclei may be released by lysing HeLa cells in solutions containing non-ionic detergents and high concentrations of salt. These nucleoids contain few chromatin proteins. We have shown that the DNA of nucleoids is quasicircular and supercoiled by measure spectrofluorometrically the amount of the intercalating dye, ethidium, bound to unirradiated and gamma-irradiated nucleoids. Ethidium binds to nucleoids in the manner characteristic of… CONTINUE READING