Patent ID: 7785880

Claim:
A method of producing a cell line that is pre-adapted for growth and transfection in serum-free medium comprising: a) transfecting an Sp2/0 cell with a first nucleic acid encoding a Bcl-EEE apoptosis-inhibiting protein to produce an Sp-EEE host cell, said protein comprising T69E, S70E and S87E amino acid substitutions; b) culturing the Sp-EEE host cell in the presence of methotrexate to amplify the first nucleic acid; c) adapting the Sp-EEE host cell to grow in serum-free medium to produce a pre-adapted Sp-EEE host cell, wherein the pre-adapted Sp-EEE host cell can be transfected in serum-free medium with a second nucleic acid encoding a recombinant protein.