Editing Adenovirus Invitrogen (section)

== ViraPowerâ¢ Adenoviral Expression System Advantages  ==

*Uses Gateway® Technology to allow highly efficient, rapid cloning of a gene of interest into a full-length adenoviral vector, bypassing the need for a shuttle vector and inefficient homologous recombination in human or bacterial cells 
*Allows generation of high titer adenoviral stocks (i.e. 1 x 10<sup>9 </sup>pfu/ml in crude preparations and 1 x 10<sup>11</sup> pfu/ml in concentrated preparations) 
*Efficiently delivers the gene of interest to actively dividing and non-dividing mammalian cells in culture or in vivo 
*Generates adenoviral constructs with such a high degree of efficiency and accuracy that the system is amenable for use in high-throughput applications or library transfer procedures 
*Allows production of a replication-incompetent virus that enhances the biosafety of the system and its use as a gene delivery vehicle

=== RCA  ===

In rare instances, it is possible for homologous recombination to occur between the E1 genomic region in 293 cells and the viral DNA, causing the gene of interest to be replaced with the E1 region, and resulting in generation of a âwild-typeâ, replication-competent adenovirus (RCA) (Lochmuller et al., 1994). This event is most likely to occur during large-scale preparation or amplification of virus, and<br>the growth advantages of the RCA allow it to quickly overtake cultures of recombinant adenovirus. As an alternative, E1-containing producer cell lines such as 911 (Fallaux et al., 1996) or PER.C6 (Fallaux et al., 1998) which contain no regions of homologous overlap with the adenoviral vectors can be used to help reduce the incidence of RCA generation