Western blot analysis showing the silencing of core protein from full-length clones of HCV by siRNA transfection. Huh-7 cells were co-transfected with pSuper-retro-siRNA74 and full-length clones of HCV using the FuGENE 6 reagent. After 48 hours, transfected cells were isolated by the treatment with trypsin-EDTA. Cells were washed once with PBS and protein lysates were prepared and electrophoresed on 10% SDS-PAGE gels. The proteins were transferred to nitrocellulose membranes, blocked and immunoreacted with a primary antibody. The membrane was washed and incubated with peroxidase labeled secondary antibody and developed by ECL-chemiluminescence method. siRNA74 inhibited the expression of core protein in the case of all three full-length clones of HCV 1a and 1b. Beta actin levels were used as a control to make sure that equal amount of protein was present in the extracts.