| Abstract: | A commercially available cationic surfactant, dimethyl-dioctadecyl ammonium bromide (DDAB), was used for making lipid vesicles.
DDAB easily dissolved in water at 60 °C and formed lipid vesicles at room temperature. The lipid vesicles showed very low
cytotoxicity compared with other cationic surfactants. After the lipid vesicles were mixed with plasmid DNA solution, the
solution was added to mammalian cells. The addition of a nonionic surfactant (Tween 80) to the cationic lipid vesicles at
the weight ratio of 1:1 enhanced transfection efficiency. Adding more or less than the optimal amounts of DNA and lipid vesicles
resulted in decreased transfection efficiency. With the optimal amounts of DNA (pCMVβ) and lipid vesicles, about 90–95% of
CHO-K1 and BHK-21C13 cells transiently expressed β-galactosidase activity 24 h after transfection. By this procedure, stable
transformants around 105 cells corresponding to 10% efficiency could be obtained by one batch transfection.
This revised version was published online in June 2006 with corrections to the Cover Date. |
