We developed a new cationic lipid suitable for use as a DNA carrier in the presence of 10% sera. The novel compound (abbreviated as Arg-Chol) contains cholesterol and a dipeptide consisting of glycine and sterically protected arginine. The efficiency of reporter gene transfection using liposomes based on this new reagent was compared with that of liposomes made with other cationic derivatives of cholesterol. Lipoplexes formulated with the newly synthesized lipid mediate in vitro transfection of B16(F10) murine melanoma cells in the presence of 10% sera more efficiently than in other cell lines and compared with other cholesterol derivatives studied.