Abstract
Negative staining of particles of the Danish F1 strain of viral haemorrhagic septicaemia virus grown in rainbow trout gonad-2 cells revealed three different types of particles: bacilliform, bullet-shaped, and long particles. The average size of the first two types was 165 x 65 nm. The long particles had a length of up to 3000 nm and showed a close resemblance to Marburg virus. Well defined surface projections could be found in all particle types. Without any special treatment we were able to demonstrate different disintegration stages of VHS virus particles in all preparations.