Abstract
Previous investigations on the persistence length of DNA in solution have revealed large discrepancies between hydrodynamic results and those from light-scattering techniques which have potentially a greater resolving power. The information obtained from experiments on a small circular DNA molecule has resolved these discrepancies. The non-superhelical circular double-stranded DNA molecule from bacteriophage [unk]X174-infected cells is small enough to permit accurate light-scattering extrapolations, and its solutions have negligible anisotropy. The persistence length obtained from experimental investigations on this molecule is comparable with that obtained by hydrodynamic techniques, even with variation of the excluded-volume factor.