RT-PCR amplification of the coding regions of the genes Bo1, Bo5, Bo6, Bo7, ORF67.5, Bo12, Bo13 and ORF75 of the BoHV-4 V.test strain. Subconfluent monolayers of MDBK cells were infected with BoHV4 V.test strain at a m.o.i. of 1 PFU/cell. 18 hours after infection, cytoplasmic RNA was extracted, purified and treated for RT-PCR. The cDNA products were amplified by PCR using specific primers listed in Table 1.