Electron Micrographs of Bacterial Cultures Infected with Bacteriophage

Abstract

Now that we have learned to recognize individual virus particles through the electron microscopy of purified suspensions it has become practical to approach the more important question of how these particles are produced within the cells they infect. Probably bacteria with their bacteriophage provide the simplest virus system immediately accessible to existing technics. This is partly because sperm-like bacteriophage particles1, 2 can easily be recognized even in the presence of other particles of similar submicroscopic size and partly because bacteria are hosts small enough to allow an electron microscopic examination of both their surface and their internal structures.To gain a satisfactory understanding of the steps involved in bacteriophage-production it is essential to be able to photograph sensitive bacteria under the conditions in which they grow and become infected. We have found that this can be done by studying replicas made of the surfaces of agar plates incubated for various periods of time af...