Ruigrok R W, Krijgsman P C, de Ronde-Verloop F M, de Jong J C
Virus Res. 1985 Jul;3(1):69-76. doi: 10.1016/0168-1702(85)90042-5.
Influenza A (X31) virus was purified over a zonal sucrose gradient. The resulting gradient fractions were examined by electron microscopy, HA and infectivity titrations and gel electrophoresis. The fractions containing a homogeneous suspension of spherical particles had the highest infectivity per amount of viral protein and a much higher HA:M ratio than the unfractionated preparation. These results explain differences in the proportions of HA and M protein we have reported elsewhere on monodisperse virus suspensions compared with earlier measurements on crude suspensions.
