Ultrastructure of bacteriophage phi 6: arrangement of the double-stranded RNA and envelope.

Pseudomonas phaseolicola cells synchronously infected with phi 6 were fixed and embedded by several procedures. The diameter of phi 6 measured 75 nm and its nucleocapsid 60 nm. Virus nucleocapsids were icosahedral and surrounded by a double membrane. In planar sections the nucleic acid appeared as a hexagonal ring and in cross section as two angular structures.