%0 Journal Article %A Takahashi, T. %A Kaga, K. %A Akahane, Y. %A Yamashita, T. %A Miyakawa, Y. %A Mayumi, M. %T ISOLATION OF DANE PARTICLES CONTAINING A DNA STRAND BY METRIZAMIDE DENSITY GRADIENT %D 1980 %J Journal of Medical Microbiology, %V 13 %N 1 %P 163-166 %@ 1473-5644 %R https://doi.org/10.1099/00222615-13-1-163 %I Microbiology Society, %X SUMMARY Dane-particle cores labelled with [3H]TTP were subjected to ultracentrifugation in a metrizamide density gradient. Two populations of core particles with different densities were obtained, and radioactivity was found only in the cores that sedimented at the lower density (1.19–1.23 g/cm3). All the cores in this group, when spread in a monolayer, were found to expel a closed circular double-stranded DNA molecule. In contrast, the core particles that sedimented at the higher density (1.23–1.27 g/cm3) were not associated with radioactivity, nor was any DNA strand extruded from them. These results show that metrizamide density gradients allow the separation of complete hepatitis B virions for the study of viral DNA. %U https://www.microbiologyresearch.org/content/journal/jmm/10.1099/00222615-13-1-163