Abstract
African swine fever (ASF) virus was grown either in swine macrophages or in VERO cells and purified free of cell DNA. Virus DNA was isolated from virions as a molecule with a sedimentation coefficient of 60S and a contour of 58 ± 3 µm. These two values give a mol. wt. of 102 ± 5 x 106 and 107 ± 5 x 106, respectively, for the genome of ASF virus. Denatured DNA fragments from ASF virus reassociate with a C0t value of 0.60 ± 0.05 Ms, which compared with the corresponding value for T4 DNA gives for the molecular mass of ASF virus DNA a value of 102 ± 8 x 106 daltons. Only virus DNA is synthesized in ASF virus-infected swine macrophages.