Abstract
The lethal effect of methylene blue (MB) plus light on extracellular phage T4o is mainly due to lesions in the DNA; the extent of this “DNA-specifity” is about 80% of that of the lethal effect of ultraviolet light. This has been concluded from marker rescue experiments performed with UV-as well as with photodynamically inactivated phages. The difference by a factor of 3.5 in the photodynamic sensitivity of T4o and T4o+ could be referred to the fact that the mutant lacks polyamines, because addition of spermine to T4o increases its resistance at least to the wildtype level. Glucose-containing and glucose-lacking T4-phages show almost the same photodynamic sensitivity so that the difference in the sensitivity of T4 and T2 probably is not due to their various degree of glucosylation.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have