Fig. 3.

CcdB gene adaptation to the adenovirus vector system and functional testing. (A) Schematic map of the ccdB gene cloned into shuttle-CMV-GFP. CcdB gene was inserted between the left and right homologous recombination arms of the shuttle vector plasmid so that it will be lost upon recombination, while if self-ligation occurs, it will block colony formation by eventually killing BJ5183 cells. (B) Functional test of cloned ccdB gene on BJ5183 cells. 25 ng of both pShuttle-CMV-GFP and pShuttle-CMV-GFP-ccdB plasmids were used to transform 200 μL of competent BJ5183 cells. The number of colonies formed per microgram of each plasmid DNA was determined as described in Section 2. Data was obtained from representative experiments performed in triplicate.