Production method of recombinant vWF high molecular weight in cell culture

Method for producing a composition of recombinant von Willebrand Factor (rvWF), the method comprising the steps of: (a) providing cell culture media baseline; (B) complement cell culture media basal copper to provide a copper concentration of between copper end 2.4 g / l and 20 g / l; (C) providing one or more cells comprising a nucleic acid encoding a protein rvWF; (D) culturing one or more cells in the cell culture media supplemented with copper so that the rvWF is expressed in and excreted from the cells in a culture supernatant in which the content of NH 4 + in the cell culture supernatant is maintained at a concentration below 4 mM; and (e) recovering at least a portion of the culture supernatant, wherein the recovered supernatant has an activity of ristocetin cofactor specific for rvWF at least 30 mU / mg of rvWF.