Fig. 8 Time-dependent transfection efficiency of KG6. KG6 was pre-incubated with the plasmid DNA in DMEM for 0 to 2 h at room temperature, and then the mixture was added to cultured cells (CHO cells). After incubation for 15 min to 2 h at 37��, the mixture was replaced with fresh DMEM containing 10% FBS, and the cells were further incubated for 24 h. The cells were harvested and the transfection efficiency was estimated by measuring the luciferase activity. The relationship between the total incubation time and the transfection efficiency is shown. Red and blue lines indicate the pre-incubation and incubation times with cells, respectively. The height of the closed circle indicates the transfection efficiency of each incubation condition.