Abstract
The development of viral neutralizing antibodies in animals injected with T3 or T4 phage is considerably inhibited by the presence of bacterial antigens. A new procedure has been described to liberate phage from infected E. coli B bacteria by inducing lysis with penicillin. By immunological means it has been shown that T4-infected cultures of E. coli B, in which phage development has been inhibited with proflavine, contain the viral neutralizing antigen after lysis. In contrast, it has not been possible to demonstrate by immunological means the appearance of viral neutralizing antigen in E. coli B infected with T3 prior to the appearance of intracellular phage.