I have a couple of questions: We decided to simply purchase concentrated lentiviral preparations of the Brunello 1 vector library (Addgene cat. no. 73179-LVC).
1. Since this is extra concentrated (1.3×108 TU, titer ≥ 5×107 TU/mL), when I perform titration to determine MOI, should I start at a much lower volume of virus--(10 uL or perhaps even 1 uL)?
2. Is there an advantage to calculating MOI with the cell titer glo assay versus simply counting cells?
3. What is the best concentration for polybrene? It seems most people use 8 ug/mL, but Doench et al. Nat. Biotechnology 2016 says it is 1 ug/mL.