A method for preparing one or more of virus particles, vectors other than viral vectors, viral vectors, whole virus, unmodified cells, modified cells, non-toxic molecules, and toxic molecules by cultivation of eukaryotic cells, comprising:
- a) cultivation of infected, virally transduced, or transfected and/or induced eukaryotic cells in a plug flow tubular bioreactor adapted for infection, viral transduction, or transfection of eukaryotic cells for a time sufficient to allow production of one or more of virus particles, vectors other than viral vectors, viral vectors, and non-toxic or toxic molecules, and
- b) controlling a pH value and/or the oxygen concentration at a beginning of passage and during passage of a mixture of cells and means for infection, viral transduction or transfection.