2.1. Cell culture and virus
Cultures of koi fin cells (KFC) were prepared as previously described
by Ronen et al. [11], using the methods of Hasegawa et al. [14] and
Neukirch et al. [15]. CyHV-3 isolated from kidneys of sick fish was
propagated in KFC cultures, as described previously [8,11].
2.2. Virus purification and DNA extraction
The culture medium harvested from infected KFC was collected and
cleared of cells and cell debris by centrifugation for 10 min at
10000 · g. The virus was then pelleted by centrifugation in a Beckman
Ti-60 rotor for 50 min at 100000 · g. Pellets were suspended in PBS,