FIG. 4.

Recombinant virus RNA synthesis. Cultures of Vero cells were infected with various recombinant or wild-type viruses at an MOI of 1.0. Intracellular RNA was isolated as described in the Materials and Methods and separated on 1% agarose gels. The RNA was transferred to a BrightStar-Plus membrane (Ambion) for 4 to 5 h and the RNA cross-linked to the membrane by UV light. The blot was probed with an N-gene-specific oligodeoxynucleotide probe (5′-CTTGACTGCCGCCTCTGCT^bT^bCCCT^bCT^bGC^b-3′), where biontinylated nucleotides are designated with a superscript b. Blots were hybridized overnight and washed with low- and high-stringency buffers as recommended by the manufacturer (BrightStar BioDetect chemiluminescent detection system; Ambion). Filters were overlaid with film and developed.