Transfection efficiency of various complexes in HepG-2 cells determined by FCM Analysis. First, 1 × 105 cells in 6-welled plates were exposed to protein-DNA complex with molar ratio of 1:2.5 (protein to DNA) with or without fusion protein, and then they were further incubated for 48 h. For flow cytometry, HepG-2 cells after transfection with pCMV-GFP were washed, trypsinized and quantified using the FACS machine as described in Materials and Methods. Data are expressed as relative percentage of GFP-expression cells/total cells(mean±standard deviation, obtained from triplicate wells). Columns represented the transfection efficiency in different complex groups: (5.2±0.23)% for Column A, (1.7±0.18)% for Column B, (43.0±1.85)% for Column C, (2.9±0.23)% for Column D, (3.8±0.32)% for Column E, (2.5±0.15)% for Column F, (3.9±0.34)% for Column G, (3.1±0.26)% for Column H, The experiments were repeated 3 times with similar results. Column C showed 8~10 folds higher than other columns in transfection efficiency (*p<0.01).