Abstract: The present invention provides a method for introducing nucleic acids into cells. The method involves exposing the cells to a compound having formula (1), in which w is a nucleic acid, x is a peptide or amino acid, y is a linker having a chain length equivalent to 1 to 20 carbon atoms or is absent, R.sub.4 is H ir CH.sub.2 O--R.sub.3 ; and R.sub.1, R.sub.2 and R.sub.3 are the same or different and are either hydrogen, methyl, ethyl, hydroxyl or an acyl group derived from a fatty acid having a carbon chain of 3 to 24 carbon atoms saturated or unsaturated, with the proviso that at least one of R.sub.1, R.sub.2 and R.sub.3 is an acyl group derived from a fatty acid, or to a compound having the formula (2): w . . . xyNHCH.sub.2 CH.sub.2 OR.sub.5, in which w is a nucleic acid, x is a peptide or amino acid, y is a linker having a chain length equivalent to 1 to 20 carbon atoms or absent, R.sub.5 is an acyl group derived from a fatty acid having a carbon chain of 3 to 24 carbon atoms saturated or unsaturated.