Switch-like gene activation: Antisense orientation of the user-selected ORF, prevents any leaky gene expression prior to Cre-mediated recombination. Other conditional gene expression systems, including LoxP-Stop-LoxP can have some low-level leaky (read-through) expression under certain circumstances.
Stable gene activation: Treatment with Cre recombinase will permanently invert the user-selected ORF to its sense orientation. Upon inversion of the ORF to its sense orientation followed by excision of one from each pair of similar LoxP sites by recombination, the ORF will be flanked by two different LoxP-variant sites which will prevent further recombination events even when Cre is present. This will allow transcription of the gene of interest, driven by the promoter chosen by the user.
Low risk of host genome disruption: Upon transduction into host cells, adenoviral vectors remain as episomal DNA in the nucleus. The lack of integration into the host genome can be a desirable feature for in vivo human applications, as it reduces the risk of host genome disruption that might lead to cancer.
Very high viral titer: After our adenoviral vector is transfected into packaging cells to produce live virus, the virus can be further amplified to very high titer by re-infecting packaging cells. This is unlike lentivirus, MMLV retrovirus, or AAV, which cannot be amplified by re-infection. When adenovirus is obtained through our virus packaging service, titer can reach >1011 infectious units per ml (IFU/ml).
Broad tropism: Cells from commonly used mammalian species such as human, mouse and rat can be transduced with our vector, but some cell types have proven difficult to transduce (see disadvantages below).
Large cargo space: The upper limit size of the adenovirus genome for efficient virus packaging is ~38.7 kb (from 5' ITR to 3' ITR). After excluding the required backbone components for adenovirus gene expression and Cre-mediated recombination, our vector has about ~7.4 kb of cargo space to accommodate the user's DNA of interest. This is bigger than the ~6.3 kb cargo space in our lentiviral conditional gene expression vector and is sufficient for most applications.
Effectiveness in vitro and in vivo: Our vector is often used to transduce cells in live animals, but it can also be used effectively in vitro. It is particularly suitable for the generation of transgenic animals with Cre-mediated conditional gene expression.
Safety: The safety of our vector is ensured by the fact that it lacks genes essential for virus production (these genes are engineered into the genome of packaging cells). Virus made from our vector is therefore replication incompetent except when it is used to transduce packaging cells.