Fig. 4
Fractionation of disrupted wild-type and HA(−) virions by glycerol density gradient centrifugation. Purified wild-type virus (a, c, e, g) or HA(−) virus (b, d, f, h) was disrupted by TritonX-100. The samples were subjected to 20–60% glycerol density gradient centrifugation. Eleven fractions were collected from the top of the gradient and numbered in ascending order from the top of the gradient to the bottom. a, b Each fraction was subjected to SDS-PAGE, followed by Oriole staining. c–h The presence of NS vRNA (c, d) 18S rRNA (e, f), and 28S rRNA (g, h) was examined by northern blot analysis using a digoxigenin-labeled oligonucleotide probe that bound to NS vRNA, 18S rRNA, or 28S rRNA (nucleotide positions 1081–4679). The numbers at the top of the panel denote fraction numbers
