Abstract
An upper limit for beta-galactosidase transfer between mating F(+) and F(-)Escherichia coli has been determined by a new technique which relies on selective lysis of the donor strain by heat induction of a thermo-inducible strain of lambda, accompanied by chymotryptic digestion of the released beta-galactosidase. No significant transfer of beta-galactosidase during mating between F(+) and F(-) cells has been observed: 0.05 +/- 0.05% of the enzyme originally present in the male cells is found in the female cells after 1 hr of mating at 37 C.