Phage infects Pseudomonas syringae pathovars and is the type organism of the Cystiviridae and has an external membrane, a lipid envelope: inner protein, outer lipid. The capsid functions of phi6 were found to be comparable to members of eukaryotes-infecting Reoviridae. When the lipid envelope is removed by organic solvents, the viral particle shows hexagonal icosahedral structure with 50 nm diameter. The intact complete phage with lipid layer has a diameter of 60 to 100 nm.