[1] Like many phages, it has been used in molecular biology to induce mutations in cultured bacteria and to introduce foreign genetic material.

[3] Traditionally, P22 is associated with viruses with similar genomic transcription patterns and life cycles including bacteriophage λ and all the other lambdoid phages.

[4] Other relatives with similar short-tailed morphology and DNA homology in the protein genes of the virion include bacteriophages λ and Ε34.

[3] P22 has a linear, double-stranded DNA chromosome within its virion that is about 44 kilobases long with blunt ends and a circular genetic map.

[3] Prior to leaving the host cell, virion chromosomes are packaged into capsids from concatemers of the sequence that result from rolling circle DNA replication.

After host infection, the linear P22 virion DNA is circularized by a homologous recombination event between the direct repeats at both ends of the chromosome.

Infection begins when the gp9 tailspike of the P22 phage binds to the O-antigen lipopolysaccharide on the surface of Salmonella typhimurium host.

[1] In the lytic pathway, viral replication proceeds immediately following infection and releases approximately 300–500 phage progeny via cell lysis within an hour.

[6] These three proteins appear to polymerise onto the newly filled capsids to form the neck of the mature phage through which DNA will be injected into a cell.

[8] In particular, P22 is stable in storage, high-titer stocks are easily obtained, and high-frequency transduction (HT) and integration-deficient mutants have been isolated.