Abstract
When cells of Escherichia coli whose synthetic capacity has been lost by heavy irradiation of ultraviolet light are infected with bacteriophage T2 inactivated by the same irradiation, a considerable amount of protein is found to be synthesized. It is evident that this protein synthesis can be induced by infection with inactive bacteriophage. The protein synthesis occurs also in unirradiated normal cells infected with inactive bacteriophage. In view of various observations in these cases, it is most probable that these proteins are equally abnormal proteins produced by bacteriophage infection. None of them has phage antigenicity. The studies in order to get several informations upon these proteins are the principal subjects of this paper.
