Inactivation by ultraviolet light of an acriflavine-sensitive gene function in phage T4D.

Mutants of phage T4D can be isolated which multiply in the presence of concentrations of acriflavine inhibitory to the growth of wild-type phage. Bacteria mixedly infected with resistant and sensitive phage are unproductive in the presence of acriflavine. Irradiation of the sensitive phage with ultraviolet light results in inactivation of the function of the gene for acriflavine sensitivity, permitting the mixedly infected complexes to yield phage. This function is inactivated in an exponential manner and has a cross section comparable to cross sections of other gene functions in T4D.