Figure 1

A. Representative plaque assays of cytopathic (cp) BVDV in MDBK cells. Cells were infected with 10-fold serial dilutions of BVDV stocks from virus supernatant. After adsorption, monolayers were overlaid with DMEM/5% horse serum and 0.5% agarose plugs. After 72 h incubation, the plugs were removed and the monolayers stained with 1% crystal violet. B. Growth Kinetics of cp BVDV in MDBK cells. Cells were infected with BVDV at MOI of 0.1. The supernatant (media, diamonds) and cell lysates (lysate, squares) were harvested at the indicated time points. Viral titers were determined via plaque assay. The results are given as log10 pfu/ml. C. BVDV RNA synthesis at various times post infection. MDBK cells were infected with BVDV as above and total cellular RNA was collected at 0 h (after 1 h adsorption), 6 h, 12 h, 18 h, and 24 h.p.i. To determine the amount of viral RNA in the cells, RT-PCR was performed with a probe specific to BVDV NS4B sequence. The amount of BVDV RNA was determined relative to GAPDH. D. BVDV NS4B cDNA products from RT-PCR, prior to quantitation, were run on 0.8% agarose gel and stained with ethidium bromide. Notice the increase in cDNA product from 6 to 24 h post BVDV infection.