FIG. 4.
Pulse-chase analysis of the PRRSV N protein. Following 1 h of starvation in deficient medium, PRRSV-infected cells were pulse-labeled at 32 h p.i. for 30 min in medium supplemented with either 150 μCi of [35S]methionine/ml (A) or 500 μCi of 32Pi/ml (B) and then chased for the indicated time intervals. At various time points postlabeling, cells were harvested and the lysates were reacted with an N-specific MAb mixture. The immunoprecipitated proteins were separated by SDS-12% PAGE and visualized by autoradiography. Mock-infected cells were harvested immediately following the pulse-label (lane 1). The chase times (in hours) are displayed above the panels.