Accession Number:

ADA170415

Title:

Spectroscopic Search for Resonant Excitation of DNA by Microwaves.

Descriptive Note:

Final rept. 11 Jul 84-ll Jul 86,

Corporate Author:

ARIZONA STATE UNIV TEMPE DEPT OF PHYSICS

Personal Author(s):

Report Date:

1986-07-16

Pagination or Media Count:

24.0

Abstract:

Inelastic laser light scattering is used to probe the vibrational modes of DNA that lie in the microwave frequency region. We have studied acoustic collective or sound wave vibrations in the region 7 - 20 GHz. in DNA films as they are hydrated. Taken together with an extensive study of the other physical properties of these films, these data show that strong interactions between phosphates dominate the dynamics in hydrated fibers. The relaxation of the hydration shell using Brillouin scattering is also studied. At GHz. frequencies, water couples strongly to acoustic vibrations. The viscoelastic transition frequency of the water at primary sites is about 4 GHz. while the secondary hydration shell undergoes this transition at about 80 GHz. Between these frequencies, there are coupled excitation of the DNA and its hydration shell which may account for the observed resonant microwave absorption. Direct spectroscopic evidence of these excitations was searched for without success. It is possible that an applied coherent microwave field must be applied to drive them.

Subject Categories:

  • Organic Chemistry
  • Atomic and Molecular Physics and Spectroscopy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE