R17 bacteriophage

1,9-Dimethylmethylene blue is a photosensitizer, virus inactivator and hemoglobin oxidant derived from methylene blue. When activated, 1,9-Dimethylmethylene blue generates reactive oxygen species including singlet oxygen, and acts as a metachromatic dye. When activated in monomeric or dimeric form, 1,9-Dimethylmethylene blue induces photoinactivation of R17 phage and vesicular stomatitis virus and oxidizes hemoglobin via non-singlet oxygen reactive oxygen species or singlet oxygen-mediated pathways, respectively. The monomeric form, with higher nucleic acid affinity, achieves virus inactivation under specific conditions without forming methemoglobin. 1,9-Dimethylmethylene blue binds to substances such as glycosaminoglycans to produce color changes. Although it is susceptible to interference from non-glycosaminoglycan components in urine, it is still applicable to spectrophotometric analysis for glycosaminoglycan quantification. With these unique photochemical and binding properties, 1,9-Dimethylmethylene blue is widely used in studies of viral infections and related biochemical analyses .