Some characteristics of salt-dependent haemagglutinating measles viruses.

Several strains of measles virus which did not agglutinate monkey erythrocytes in phosphate-buffered saline did so in buffer containing 0-8 M-ammonium sulphate. Haemadsorption to cells infected with these viruses was also salt-dependent. In a series of tests salt-dependent agglutinin was shown to be a stable structural component of the infectious virion. The relevance of these findings is discussed in the light of previous reports that many measles virus preparations do not agglutinate erythrocytes.