The ultraviolet light and photosensitized inactivation of tobacco mosaic virus.

The quantum yield for the inactivation of tobacco mosaic virus has been determined at 253.7 mmicro and found to be 4.3 x 10(-6). The possible significance of the observed one-hit process of inactivation has been discussed in terms of the kinetics and the rupture of model substances including nucleic acid. The ultraviolet light inactivation, which proceeds independent of oxygen, occurs without change in physicochemical properties, with the possible exception of an enhanced sensitivity to thermal denaturation. The photosensitized inactivation of virus by acriflavine has been found to proceed parallel with the destruction of the dye. The action was found to be dependent upon adsorbed dye, and the inactivation is enhanced by the presence of oxygen.