Effect of UV irradiation on transduction by coliphage T1

Lysates of the virulent coliphage T1 transduce seven markers between strains of Escherichia coli with reproducilble efficiencies which range from 10(-7) to 10(-5). The ability of a UV-irradiated lysate to transduce Arg(+), Str(R), Trp(+), Lac(+), and Pro(+) is 90% and Bio(+) is 99% inactivated by doses which inactivate plaque formation of T1 by six orders of magnitude. A dose of irradiation which causes a 1- to 2-log drop in the titer of T1 stimulated Gal(+) transduction by two- to three-fold; no other marker tested was stimulated. Irradiation causes dislinkage of some co-transducible markers but not others.