FIG. 3.
Quantitative analysis by PCR of capsids released. (A) Various amounts of purified HSV-1 DNA were amplified by PCR with UL20-specific primers under limited cycling conditions (see Materials and Methods). (B) The viral DNA from increasing numbers of nuclei isolated from infected cells was extracted and amplified by PCR as described above. (C) Nuclei isolated from HSV-1 17+-infected cells were incubated in vitro 6 h at 4°C or 37°C in the presence (4 mg/ml) or absence of cytosol from infected cells and with (+) or without (-) an energy regeneration system. Capsids released in the assay were separated from nuclei on spin columns, and DNA was extracted from the capsids and amplified by PCR as described in the text. PCR controls: -, no DNA; +, DNA from HSV-1 17+-infected cells.