The present invention refers to the transfection of cells using a conjugate comprising at least one saccharide residue at least one nucleosidic component selected from nucleic acids, nucleosides and nucleotides. This conjugate is suitable for the transfection of prokaryotic and eukaryotic cells such as plant cells or mammalian cells including human cells with high efficacy. Thus, a new delivery vehicle for therapeutic molecules including antisense molecules, sRNA molecules, miRNA molecules, antagomirs or precursors of such molecules, as well as the therapeutic nucleosides or nucleotides, is provided. Further, a convenient strategy for developing new lines of plants that exhibit particular traits is provided.