Lab Note A simple protocol for producing high-titer lentivirus

Gene function studies require loss-of-function phenotypes, which can be achieved either by the generation of gene knockout (KO) animal models or by RNA interference (RNAi) methods. Compared with KO approaches, RNAi is more time- and cost-effective. Furthermore, KO technology was mostly applied on mice so far, with only a few studies on other animal models such as rats and pigs, which also limits its application [1,2]. Comparatively, RNAi can work on a much wider spectrum, from Caenorhabditis elegans to mammals [3–5]. Lentiviral vectors are useful tools for RNAi because of their ability to transduce non-dividing cells and achieve stable and long-term transgene expression. Moreover, they do not induce a cellular immune response. Lentiviral vectors producing shRNAs have been shown to knockdown gene expression both in vitro and in vivo [6–9]