FIG. 6.
RNA synthesis in recombinant and wild-type viruses. Cultures of cells were infected with wild-type MHV or recombinant viruses, and intracellular RNA was harvested from DBT cells at 12 hpi. RNA was separated on a 1% agarose gel, transferred to nylon filters, and hybridized with a biotinylated RNA probe specific for N protein mRNA. The filters were incubated with a chemiluminescent substrate and exposed on film.