Spectral Difference of the A and B Forms of Deoxyribonucleic Acid

Infrared absorption spectrum of an oriented film of deoxyribonucleic acid from Micrococcus lysodeikticus has been examined in its A and B forms. In the A form a weak band was observed at 807 cm−1, while in the B form this is absent and a broad and weak band appears at 832 cm−1.