... of PBS. Calculate the fraction of fluorescent-positive cells in each well. When calculating titer, only...fluorescent cells Equipment Class II, Type A2 Biological Safety Cabinet 0.5–10 µL single channel pipette...mL), Millipore TR-1003-G 1X PBS pH 7.4 without calcium or magnesium, Corning 21-040-CV (cations can affect...tissue culture treated dish, Corning 3516 15 mL conical tubes, VWR 21008-216 Lentivirus preparation Reagent...You Start The health of the target cell line is critical for obtaining accurate titers. Check the cells...remaining well, a cell count is required for calculating the titer. Incubate for 48–72 h. Gently aspirate...leading to underestimation of the true titer. Calculate the transduction units per mL (TU/mL) using either...