Colson P, Houssier C
Laboratoire de Chimie Macromoléculaire et Chimie Physique, Université de Liège, Belgium.
FEBS Lett. 1989 Oct 23;257(1):141-4. doi: 10.1016/0014-5793(89)81806-x.
Polyamines (spermine, spermidine) are commonly used as stabilizing cations in the chromatin preparation media. Their residual binding to chromatin is not easily reversed at low ionic strength, even after extensive dialysis, as evidenced by the use of labelled spermidine. Electric dichroism measurements show that their presence interferes with the physico-chemical characterization of chromatin by maintaining a condensed structure. These results give a definite answer to the controversy about the sign of optical anisotropy of chromatin determined by electric and flow dichroism techniques.
