[Conditions of formation of DNA optically-active particles in polyethyleneglycol-containing solutions of different...

Conditions of formation of the DNA optically-active compact particles (e. g. particles which are characterized by intense negative band in CD spectrum) in PEG-containing solutions of NaCl, NaClO4, KCl, KBr, KI and CsCL have been studied. It has been shown that the region of existence of the DNA optically-active compact particles is restricted not only by the definite concentration of PEG, but also by the definite ionic strength of solution. Above this region the intense band in CD spectra of the DNA compact particles is practically absent. The nature of cation influences the process of compactization (condensation) of the DNA double-stranded molecules; the nature of anion does not influence this process (up to 0,3 M salt concentration).