A. If the RNAi sequence is getting into the cell and just not knocking it down enough, we will try another sequence or a combination of sequences. Invitrogen sells “smart pools” of RNAi’s consisting of four or five sequences. Sometimes you can get better knockdown just by shifting the sequence a couple of nucleotides. If the RNAi isn’t getting into the cell (test by uptake of a labeled oligo, e.g. Block it by Invitrogen) we will try other transfection reagents or may engineer into a viral vector (e.g. lentivirus, herpesvirus, etc.).