Characterisation of an epizootic haemorrhagic disease virus

A high titre of epizootic haemorrhagic disease (EHD) virus was obtained from roller bottles of African green monkey kidney (Vero) cells. Cell associated EHD virus was purified by use of Genetron-113 and sonication. Purified viral particles were probably icosahedral with a diameter of 58 nm and contained capsomeres which appeared to be composed of five and six subunit structures. Phenol extracted nucleic acid from purified EHD virus when treated with orcinol or diphenylamine gave colour reactions and ultraviolet absorption spec-trums characteristic for ribonucleic acid (RNA). EHD viral RNA had a melting temperature of 86°C in 0.015 M NaCl-0.0015 M sodium citrate. RNA from EHD virus did not react with formaldehyde, but after it was heated at 102°C for 10 min hyperchromicity was observed. Electrophoresis of EHD-RNA in 5 per cent polyacrylamide gels showed the genome to be composed of at least five different segments.