On day 1, 1 × 105 BALB/MK cells and 1 × 106 PA317/LBmSN cells were seeded in 25 cm2 flasks. On day 2, the medium from the PA317/LBmSN cells was replaced with EMEM supplemented with 10 % FBS and without EGF. On day 3, the medium of the PA317/LBmSN cells containing virus was harvested, centrifuged at 10,000 rpm per 1 min in an Eppendorf centrifuge. The medium of the BALB/MK cells was replaced with 4 ml of the virus solution and complemented with EGF and Polybrene at a final concentration of 5 ng/ml and 8 μg/ml respectively. On day 4, the cells were trypsinized and seeded in the 24 well plate at the indicated number of cells containing 8 μg/ml BS.
1 Results are the means ± S.D. of three experiments.