A method for grafting a porous element for leucodepletion by adsorption and/or filtration of a biological fluid, such as blood or a blood component, which method comprises the steps of impregnating the porous element with a solution containing a poly(ethylene oxide) having identical or different functional end groups and applying an ionizing treatment to the impregnated porous element so as to ensure covalent cross-linking between the poly(ethylene oxide) and the porous element.
