Exponentially growing HeLa pLuc705 cells (1.75 Â 10 5 cells seeded and grown overnight in 24-well plates) were co-incubated with the (R-Ahx-R) 4 -PMO conjugates and with 20 mg/ml saponin for 30 min. The conjugates were removed and the cells were washed twice with PBS and incubation continued for 24 h in complete medium (DMEM plus 10% FBS). Cells were washed twice with ice-cold PBS, lysed with Reporter Lysis Buffer and processed as described above.