The mechanism of release of φX174 by infected E. coli is of interest since its
understanding must result in the discovery of either: (1) a phage-specific lytic enzyme
(Streisinger, Mukai, Dreyer, Miller & Horiuchi, 1961; Jacob & Fuerst, 1958) which
would be the first example of a φX-specific enzyme; or (2) a novel method of phage
release. Recently some unsuccessful attempts to detect a lytic enzyme in the mature
phage particle and in infected cells have been reported (Fujimura & Kaesberg, 1962;
Eigner, Stouthamer, Van der Sluys & Cohen, 1963). It has been suggested (Eigner
et al., 1963) that release of φX precedes cellular dissolution. Denhardt (1963, in
preparation) has shown that even when the infection process is synchronized by
infection in the presence of 0·003 M-KCN or by 'infection of starved cells phage
release occurs over a period of time longer than the minimum latent period. These
results suggested the possibility that ,PX might be released slowly from single infected
complexes, as is the case with certain animal viruses (see, for example, Dulbecco &
Vogt, 1954), rather than in bursts occurring at the time of lysis