The photodynamic inactivation of λ bacteriophage particles in the presence of methylated proflavine

The DNA of bacteriophage λ, which had been inactivated by irradiation with visible light in the presence of methylated proflavine, was examined by electron-microscopy and by the loss of infectivity, to identify the molecular alterations responsible for dye-sensitized photoinactivation. Large doses of visible light led to breakage of the polynucleotide strands and to crosslinking between DNA and proteins. In the low dose range, the participation of the recombination and excision functions in the repair of DNA is demonstrated. © 1971.SCOPUS: ar.j