Can not reduce protein level - (Jun/24/2012 )

Dear all,
I have a big problem on my RNA silence experiment. I try to knock down SR-BI. I have reached 70 percent decrease in mRNA level after 72h transfection, but did not see effect on protein level. Then I tried to do transfection twice at 72h interview. First, I transfect in 12 well plate, after 72h, I did transfection again, but scaled to 6 well plate because I got 80-90 percent confluence of cells in 12 well plate. However, I still do not get effect on protein level, and I saw many cells were dead. I do not know what to do next. Is there any problem with my protocol? Could anyone give some suggestions?
Thanks a lot!
Yue

Maybe you could check this post.

http://www.protocol-online.org/forums/topic/24275-rnai-problem-gene-is-knocked-down-but-not-protein/