Wallis, Craig (Baylor University College of Medicine, Houston, Tex.), and Joseph L. Melnick. Photodynamic inactivation of enteroviruses. J. Bacteriol. 89:41-46. 1965.-Enteroviruses are usually resistant to photodynamic inactivation, but they can be rendered completely photosensitive to proflavine at pH 9 to 10, if they are first purified by filtration through an anion resin. In addition, if enteroviruses are grown in cells maintained in a salt-glucose medium, they can be photosensitized. Of 38 enteroviruses tested, 10 were rendered completely photosensitive to proflavine, or toluidine blue, or both, and the remaining 28 viruses were sensitized, but to a lesser degree. The binding of dye to the virus can be reversed by lowering the pH.