Abstract: A method of recovering mammalian cell clones adapted to serum and protein-free media is disclosed. The procedure includes a two-stage adaptation process to grow in that condition. A critical protein concentration interval is disclosed in which cells must grow in order to gain the capacity to survive in serum and protein-free condition, once the cells have grown at the critical interval concentrations, subsequent decreases of the concentration will affect neither viability nor cellular doubling time. The critical protein concentration interval is cell line specific. Furthermore, mammalian cells clones are disclosed, which are stable in serum- and protein-free media for at least 40 generations; additionally, clones disclosed express a recombinant product. The cell clones disclosed produce the humanized anti-EGF-R antibody hR3, the humanized anti-CD6 antibody T1hT, the chimeric anti CD3 antibody T3Q, or fragments thereof.

Abstract: The present invention relates to a method of recovering mammalian cell clones adapted to serum and protein-free media, the procedure includes a two-stage adaptation process to grow in that condition. The present invention discloses a critical protein concentration interval in which cells must grow in order to gain the capacity to survive in serum and protein-free condition, once the cells have grown at the critical interval concentrations, subsequent decreases of the concentration will affect neither viability nor cellular doubling time. The critical protein concentration interval is cell line specific. Furthermore, in the present invention mammalian cells clones are disclosed, which are stable in serum- and protein-free media for at least 40 generations; additionally, clones disclosed in the present invention express a recombinant product.