Fig. 4From: Developing a vaccine against velogenic sub-genotype seven of Newcastle disease virus based on virus-like particlesA) VLP of Newcastle disease virus (NDV) in sucrose gradient. The Sf-9 cells were transfected with recombined BAC-mid. After 96 h, the supernatant was carried out on 20% and 65% sucrose (centrifuged at 32,000 rpm for 5 h). B) Electron microscopy: NDV-VLPs.Back to article page