Fifty-three years since Hershey and Chase; much ado about pressure but which pressure is it?

The events that occur at the initiation of phage infection are discussed, from adsorption through DNA ejection from the virion into the cell. A new model for DNA translocation is described that not only overcomes difficulties associated with previous models of DNA ejection but also provides a mechanism by which both single-stranded genomes and internal phage proteins can be transported from the virion into the cell cytoplasm.