Patent ID: 8084251
Filing Date: 2011-12-27
Classification: C12N

Abstract:
1. A stable recombinant mammalian cell clone, obtainable by a method comprising: providing a recombinant original individual mammalian cell clone, wherein the original individual mammalian cell clone has a selection marker, cultivating the recombinant original cell clone on serum-containing medium, adapting the cells to serum- and protein-free medium with neither selection pressure for the selection marker nor selection for a polypeptide factor that replaces serum components, testing the cell culture after adaptation for stable product-producers with neither selection pressure for the selection marker nor selection for a polypeptide factor that replaces serum components, and cloning a stable product-producer-cell clone in serum- and protein-free conditions with neither selection pressure for the selection marker nor selection for a polypeptide factor that replaces serum components; wherein the cell clone is stable for at least 40 generations and expresses a recombinant product under production conditions in serum- and protein-free medium, with neither selection pressure for the selection marker nor selection for a polypeptide factor that replaces serum components.