How are they different from other viral-based siRNA vectors on the market?
Currently, we are only aware of Invitrogens HIV-based RNAi Expression System. As opposed to our FIV-based expression system, Invitrogens system is complicated by extra steps, requires the end user to clone their siRNA insert into the pENTR/U6, and then perform a recombination reaction between the pENTR/U6 entry construct and the pLenti6/BLOCK-iT-DEST to generate the pLenti6/BLOCK-iT expression construct. In addition to the extra steps and time required, Invitrogens Lentiviral vectors and packaging system are 3 times more costly. This does not include the increased costs of using the Gateway reagents (as compared to the costs of standard cloning reagents used by SBIs Expression System) required through their use of the Gateway cloning system. The unique pFIV Double-Promoter siRNA vector. SBI is the only company to offer a double promoter vector that expresses siRNA directly. Instead of cloning a much longer template sequence that expresses a hairpin siRNA, the double promoter vectors on
