FIG. 5.

Physical separation of enveloped particles by density gradient centrifugation. Extracellular particles in the day 7 and day 8 supernatants of PTHs transduced with Ad-HBV1.3 at an MOI of 100 were concentrated by PEG precipitation and centrifuged through a CsCl gradient. Because no protease treatment was included, naked cores and Ad-HBV particles were left intact. The density and HBsAg profiles are shown in the graph. Subsequently, DNAs contained in fractions 7 to 18, covering a density range from 1.16 to 1.42 g/ml, were extracted and analyzed by Southern blotting using a DIG-labeled HBV probe as described in the legend to Fig. 4. HBV RI, replicative intermediates; St, 50 pg of a 3.2-kb linear HBV genome; M, DIG-labeled DNA marker with fragment sizes in kilobases.