title: Structure of native and chloroform-methanol-treated mycobacteriophage R1.
abstract: The morphologies of native and chloroform-methanol-treated mycobacteriophage R1 were compared by electron microscopy, utilizing three negative stains. R1 was determined to be a complex phage. The head appears as an elongated cylinder with a pointed end (93 +/- 3 by 42 +/- 3 nm) constructed from an orderly arrangement of capsomeres. The phage tail measures 209 +/- 11 by 11 +/- 1 nm and possesses a striated surface with two base plates at its distal end. Treatment of R1 with chloroform-methanol resulted in disruption of both the head and tail structures and was accompanied by loss of infectivity. However, because no likely lipid-containing structure was observed in native phages, there is the possibility that the mechanism of chloroform-methanol inactivation is something other than lipid extraction.
mesh_terms: D002725:Chloroform / Q000494:pharmacology; D000432:Methanol / Q000494:pharmacology; D009160:Mycobacteriophages / Q000187:drug effects / Q000648:ultrastructure*; D014764:Viral Proteins
chemical_list: D014764:Viral Proteins; D002725:Chloroform; D000432:Methanol