1- Viral particles quality. Ensure that the ratio total/infectious particles number is correct
2- Expression cassette. Make sure that the transgene is well expressed in vivo, meaning that the expression cassette (promoter, terminator…) is suited for in vivo.
3- Route of Injection. In order to improve your transduction, prefer a route of injection close to your target tissue; e.g. inject your vector intra-arterially into the tissue supplying artery (use the same quantity as intravenous administration, be careful, intra-arterial manipulations enhance the risk of thrombosis) or directly into the tissue of interest together with magnet application.
4- Medium used for preparing transduction complexes. Favour saline buffer (HBS, PBS, normal saline, Ringer’s solution) or 5% glucose during the preparation of the complexes.
5- Injection volume. Optimize the volume of injection to your application.
6- Speed of injection. DNA expression could be dependent on the injection speed, adapt your speed of injection to your target tissue.
7- Transduction reagent temperature. Reagents must be at room temperature and be vortexed prior to use.
8- Old transduction reagent / DNA complexes. The transduction reagent / viral particles complexes must be freshly prepared every time. Complexes prepared and stored for longer than 2 hours can be aggregated.
9- Incubation time. Optimal time range between transduction and assay varies with tissue, promoter, expression product, etc. Transduction efficiency can be monitored after 4 – 48h by analyzing the gene product.
- Injection solution. Prefer 5% glucose (final concentration) than saline buffer (HBS, PBS, normal saline, Ringer’s solution).