COMPARISON OF CALCULATED AND OBSERVED CD SPECTRA OF LIQUID-CRYSTALLINE DISPERSIONS FORMED FROM DOUBLE-STRANDED DNA AND FROM DNA COMPLEXES WITH COLORED COMPOUNDS

The CD spectra of dispersions of DNA, in the form of cholesteric liqui d crystalline droplets, in an aqueous continuum have been studied. Cal culated curves have been fitted to experimental spectra. The amplitude and the sign of the intense absorption band of the purine and pyrimid ine bases vary with the droplet size, the pitch and the twist sense of the cholesteric phase. The CD spectra of dispersions of the complex f ormed by DNA and a coloured intercalating antibiotic have been similar ly studied. A general satisfactory level of fitting between observed a nd calculated CD spectra was found.