Polyamines contained by two densonucleosis viruses.

Densonucleosis viruses 1 and 2 both contain the three polyamines putrescine, spermidine, and spermine in complete virus particles but not in their respective top components. The polyamines, with spermidine predominant, comprise 1.41% of the virus particle by weight, which is sufficient to neutralize 26% of the single-stranded DNA contained within the particles.