We have investigated the mechanism of virus photoinactivation with methylene blue (MB) by conducting deuterium oxide (D 2 O), azide ion (N 3 -) and oxygen- dependent studies. Inactivation of M13 bacteriophage and singlet oxygen ( 1 O 2 ) generation by MB photosensitization were irradiation dose dependent. Inactivation of M13 was enhanced by D 2 O and inhibited by N 3 -, suggesting that 1 O 2 participates in M13 inactivation by MB photosensitization. However, N 3 -did not inhibit M13 inactivation completely. On the other hand, deoxygenating the reaction solution still caused 52-67% of M13 inactivation observed in the presence of oxygen. These results suggest that 1 O 2 -mediated (Type II) and sensitizer-mediated (Type I) reactions may both play roles in M13 inactivation by MB photosensitization.
H. Abe, K. Ikebuchi, S. J. Wagner, M. Kuwabara, N. Kamo, S. Sekiguchi, "Potential Involvement of Both Type I and Type II Mechanisms in M13 Virus Inactivation by Methylene Blue Photosensitization," Photochem Photobiol,66, 204 (97).