Isolation and Properties of Newcastle Disease Virus Nucleocapsid

Abstract
Deoxycholate (DOC) disrupted virions of Newcastle disease virus (NDV), releasing viral nucleocapsids. The nucleocapsids sedimented at about 200 S in sucrose gradients and measured from 1.3 to 1.4 μ long by electron microscopy. NDV nucleo-capsids were resistant to pancreatic ribonuclease. These nucleocapsids contained all the 50 S ribonucleic acid (RNA) in NDV virions, while virus-associated RNA sedimenting at less than 50 S was external to the virions.