Functional virus titer via gene transfer assay
Suspension-adapted HEK293SF cells were transduced with serial dilutions of AAV6-GFP and co-infected with an E1, E3-deleted adenovirus serotype 5 (∆E1E3Ad5) at an MOI of 5 infectious particles/cell. At 24 hours post-transduction, the cells were harvested and fixed in 2% paraformaldehyde at 4°C for 30 min. Cells were analyzed using a BD Accuri C6 flow cytometer (BD Biosciences, USA), and EGFP expression was analyzed using BD Accuri C6 Plus Analysis Software (BD Biosciences, USA). The linear range of quantification was established between 2%–20% of GFP-positive cells [59].