Specificity of anti-F dsRNA. Experiments were done essentially as described for Fig. 2. A549 cells were transfected with the indicated amounts of anti-F dsRNA followed by infection by RSV as described under Materials and Methods. Top: Immunoblot of total cell extracts to detect RSV F, RSV P, and profilin; Bottom: Autoradiograph showing immunoprecipitated metabolically 35S-labeled RSV proteins. 'U' represents uninfected cells. Note the specific loss of F protein, but no effect on other proteins.