Fig 3.

Cotransfection of PreXMRV-1 and PreXMRV-2 produces replication-competent virus. (A) Protocol. Supernatants were harvested at 7 days postcotransfection of 293T cells with PreXMRV-1 and PreXMRV-2 (6 independent cotransfections) and then split to infect either DIG or 293T target cells. The DIG cultures were monitored every 3 days for GFP-positive cells; concurrently, 293T cells were split every 3 days and frozen, and DNA was extracted. (B) FACS analysis of DIG cells at 3, 6, and 10 days postinfection for infections labeled A to F.