The flow linear dichroism of DNA: Comparison with the bead‐spring theory

Abstract

Abstract The flow linear dichroism if T7 bacteriophage DNA has been obtained as a function of velocity gradient in neutral aqueous solutions containing 0.15 M Na + or K + . The data are compared with the hydrodynamic bead‐spring theory of Rouse and Zimm using currently available spectroscopy, structural, and hydrodynamic parameters. Good agreement between theoretical and experimental isocline angle behavior is found. The magnitude of the measured linear dichroism is not in exact agreement with theory when presently accepted stiffness and optical parameters are used. Agreement is improved either by assuming a shorter persistence length or a less negative value for the limiting dichroism of DNA.