The ultraviolet absorption of desoxyribonucleic acids DNA in neutral saline solution is much lower than that expected from the sum of the absorptions of its constituents. The observed spectrum can be made to approach the calculated one by applying mild treatments which are presumably without action on phosphoester linkages pH, temperature and salt concentration changes. The incidence of these facts on the questions of the chemical structure and biological properties of DNA is discussed. The results are interpreted as reflecting a denaturation of the DNA, i.e. the destruction of a secondary molecular structure constituted by labile bonds involving the puric and pyrimidic rings. Author
Trans. of Biochimica et Biophysica Acta (Netherlands) v14 p231-240 1954.