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Photobiological Properties of Methylene Violet *
Author(s) -
Morrison Harry,
Mohammad Taj,
Kurukulasuriya Ravi
Publication year - 1997
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1997.tb08650.x
Subject(s) - singlet oxygen , photochemistry , methylene blue , chemistry , dna , absorption spectroscopy , visible spectrum , spectroscopy , nucleic acid , absorption (acoustics) , covalent bond , methylene , irradiation , oxygen , materials science , organic chemistry , photocatalysis , optoelectronics , biochemistry , physics , quantum mechanics , nuclear physics , composite material , catalysis
The interaction of methylene violet (MV) and 4‐bromo‐methylene violet (BrMV) with calf thymus and super‐coiled φX174 phage RF I DNA is reported. Measurements employing UV‐visible absorption spectroscopy and equilibrium dialysis give evidence for the formation of complexes by each dye with DNA in the dark. They covalently bind to DNA, and MV nicks DNA, when the nucleic acid/dye mixtures are irradiated with visible light in a deoxygenated environment. Quantum efficiencies for singlet oxygen formation are 0.27 and 0.25 for MV and BrMV, respectively. A higher value (0.49) is observed for 4‐iodomethyIene violet (IMV). Summary The MV and BrMV interact with DNA in the dark to form complexes that are observable by absorption and emission spectroscopy and by equilibrium dialysis. When mixtures of the dyes and DNA are irradiated with visible light, both incorporation of the dye into the nucleic acid and nicking of the DNA are observed. These dyes generate singlet oxygen with quantum yields ranging from 0.25 for MV to 0.49 for IMV.