Figure 4.

Schematic representation of the improved retrovirus three plasmid co-transfection system. Viral genome is segregated into three expression plasmids; the vector genome, the Gag/Pol expressing plasmid, and the envelope expressing plasmid. For generation of viral particles, these plasmids are co-transfected into the HEK 293 producer cells, and virus is released into the supernatant.