SUMMARY: Particles of influenza, mumps, fowl plague, Newcastle disease and Sendai viruses were adsorbed on electron microscope films and treated with acid, trypsin and ribonuclease. All of these viruses contained trypsin-resistant rings of ribonucleoprotein and with some strains these rings showed lines of staining which may indicate the arrangement of the nucleic acid.
KuroyaM.,
IshidaN.,
ShiratoriT.1953; Newborn virus pneumonitis (type Sendai). II. Report: The isolation of a new virus possessing haemagglutinin activity.. Yokohama med. Bull. 4:217