Timothy I. Aoki, Patrick R. Callis
Oct 22, 1982
Chemical Physics Letters
Abstract The fluorescence spectra (300–500nm) quantum yields (φf) and excitation spectra (240–285 nm) are reported for neutral aqueous sloutions of purified native DNA from calf thymus, E. coli bacterium, and hen erythrocyte near 20°C. The same properties were also measured for a reference solution of mononucleotides, and direct comparisons were made. Whether purified or not, the DNA spectra all closely resemble that from the monomer mixture between 300 and 360 nm but shows a broad, low level shoulder at λmax ≈ 450nm which is absent in the monomer spectrum. The φf for the purified DNA is (4 = 1) x 10-5, about half that of the monomer reference solution and unpurified DNA. The excitation spectrum is slightly red-shifted from the absorption for both the DNA and the monomer mixture, but not for the individual monomers. The fluorescence exhibits abrupt changes associated with the denaturation of DNA at ≈ 80°C and pII) 11.