Use of a biotinylated trans-lactam probe for the detection of HCV NS3 in vaccinia virus-infected cells. Extracts of rVV NS3-5-infected cells were preincubated with compound (Cmpd) 1q, at the concentrations indicated, for 1 h prior to the addition of a biotinylated trans-lactam probe, compound 6. Samples were analyzed by Western blotting using an HRP-neutravidin probe and were visualized by using SuperSignal reagent. Wt, wild-type vaccinia virus-infected cell extract; NS3-5, rVV NS3-5-infected cell extract.