The effects of pharmacol. agents, such as polycations on adenovirus infection were studied using two different cell systems: PER.C6 and HEK 293 cells.The infection with adenovirus in either HEK 293 or PER.C6 cells was significantly increased by the addition of polycations.In particular, the polybrene at 4 μg/mL resulted in the greatest increase of infection on HEK 293 cells at day 13.However, the addition of 100 μg/mL or 500 μg/mL protamine, 5 μg/mL poly-L-lysine, 0.5 μg/mL DEAE-dextran and 1 mM spermine before infection did not increase the efficiency of adenovirus infection in PER.C6 cells.