Solution behavior of DNA studied with magnetically induced birefringence

Magnetically induced birefringence can provide useful information on the physical properties of nucleic acids in a variety of forms. The technique is particularly sensitive to structural changes. Difficulties arise with drawing precise structural conclusions principally because of doubts about the relative contributions of the form and intrinsic components to the optical anisotropy. Nevertheless results so far suggest that this might not be a severe limitation. The induced birefringence is very sensitive to cooperative behavior; consequently the transition from an isotropic to a liquid crystalline phase can be followed in detail. Finally the high degree of magnetic orientation often achieved with liquid crystals assists their study with other physical techniques.