Gray, Horace B., Jr.2022-06-202022-06-20197423155115https://hdl.handle.net/10657/9502The sedimentation coefficient (sp[degrees]) and viscosity of closed circular bacteriophage PM2 DNA, artificially produced so as to possess a low absolute superhelix density, has been measured as a function of ethidium bromide (EB) concentration in a solvent of approximately 0.1 M ionic strength. Under these conditions, which allow the introduction of a substantial number of positive superhelical turns into the molecule with increasing ethidium bromide concentration, the hydrodynamic behavior of the closed circle is not a monotonic function of the superhelix density, and clearly displays a local minimum in the case of the s[degrees] titration curve. As such non-monotonic behavior has previously been demonstrated in the case of negative superhelix densities, it is now clear that the curve of s[degrees] vs superhelix density is non-monotonic and contains local minima on both sides of zero superhelix density.application/pdfenThis item is protected by copyright but is made available here under a claim of fair use (17 U.S.C. Section 107) for non-profit research and educational purposes. Users of this work assume the responsibility for determining copyright status prior to reusing, publishing, or reproducing this item for purposes other than what is allowed by fair use or other copyright exemptions. Any reuse of this item in excess of fair use or other copyright exemptions requires express permission of the copyright holder.Thesisreformatted digital