Abstract: The present in invention relates to a method for the separation of living cells from a mixture of dead and living cells which optionally can also possibly contain cell fragments.

Abstract: The present invention relates to processes for the targeted transfection of cells, compositions which may be used for such processes, and corresponding pharmaceutical compositions for gene therapy. In particular, the invention relates to a process for introducing nucleic acid into cells comprising the steps of (a) mixing a nucleic acid with a dendrimer, in which a proportion of the dendrimer molecules are biotinylated; (b) mixing the resulting complex of nucleic acid and dendrimer with a second complex consisting of avidin or streptavidin and a biotinylated target-specific binding molecule; and (c) incubating the complex formed in step (b) with cells. Dendrimers which are well suited to the present invention include, for example, partially solvolysed polyamidoamine (PAMAM) dendrimers. Target-specific binding molecules are, in particular, cell-type-specific markers of the cell surface of the target cells.