This book examines the peculiarities of the circular dichroism (CD) spectra of the double-stranded (ds) DNA cholesteric liquid-crystalline dispersions (CLCDs). The main physico-chemical properties formed as a result of the phase exclusion of these molecules in water-salt or water-salt-polymer-containing solutions are examined. In addition, the main principles of the theory of optical properties of imperfect, absorbing, cholesteric liquid crystals is discussed.