How the Retro-X Universal Packaging System works
Retroviral gene transfer systems depend on packaging cell lines to supply necessary viral structural proteins. The provided GP2-293 cell line contains the Moloney Murine Leukemia Virus (MMLV) gag and pol genes stably integrated into its genome. Simply transfect GP2-293 cells with the retroviral vector and the appropriate viral envelope vector, wait 48 hours, and then collect your viral supernatant which is ready for transduction (Figure 1).

Figure 1. The Retro-X Universal Packaging System. The system consists of the GP2-293 Packaging Cell Line, which expresses viral Gag and Pol proteins, and a set of 4 viral envelope expression vectors. Cotransfecting an envelope vector with your retroviral construct allows you to select the ideal tropism for your virus.