Circular dichroism of DNA--proflavine, DNA--ethidium and DNA--distamycine flow--oriented complexes

The circular dichroism (CD) spectra of flow-oriented complexes of DNA with proflavine (PF), ethidium (ET) and distamycine (DS) have been studied in the ultraviolet region. The CD spectra with light propagating in parallel to the flow direction were measured by the method of Chung and Holzwarth [1]. Delta epsilon and delta epsilon values have been obtained by this method. It was shown that all the complexes studied exhibit a strong CD anisotropy so that "isotropic" CD spectra measured with a conventional procedure can be attributed to the mutual compensation of the two components of opposite signs.