INFECTION BY BACTERIOPHAGE T5 AND ITS INTRACELLULAR GROWTH—A STUDY BY COMPLEMENT FIXATION

Infection of a susceptible bacterium by a virulent phage particle is followed, after a latent period, by cell lysis and liberation of newly formed phage particles. The infecting particle loses its infectivity shortly after adsorption to the host, a fact attributed to disociation of the particle into a-cell penetrating fraction, consting chiefly of nucleic acid, and an externally persisting fraction, consisting chiefly of protein and containing at least some of the principal phage antigens (Hershey and Chase, 1952). The study of the intracellular development of virus antigens, initiated with influenza v (Hoyle, 1948, 1952; Henle and Henle, 1949; Liu and Henle, 1951), has now been extended to phage (Rountree, 1951, 1952; DeMars et al., 1953). At present, it is generally agreed that virus antigens appear intracellularly before infectious virus. Studies with phage have been aided considerably by the discovery of methods such as the cyanide-T6 technique of Doermann (1952) for lysing infected cells at given times during the latent period. In the only available quantitative studies of the role of phage antigen in the infective proce, it has been reported (Rountree, 1951, 1952) that the complement-fixing antigen of coliphage T5 and of the staphylococcal phage 3A disappears from the system shortly after adsorption; with phage 3A, a second antigen is believed to persist externally. The present paper describes a quantitative method for complement fixation with phage and its application to the study of infection and