We report a method for introducing a glutamine synthetase (GS) selectable marker into myeloma cells in which transfectants are selected by growth in a glutamine-free medium. Vector amplification can subsequently be selected using the specific inhibitor of GS, methionine sulphoximine (MSX). Using this system, DNA sequences encoding a chimeric B72.3 IgG4 antibody were expressed from hCMV-MIE promoters in NSO myeloma cells. A cell line was isolated after a single round of selection for vector amplification which contains approximately 4 copies of the vector, secretes 10-15 pg/cell/day cB72.3 antibody during exponential growth and can accumulate 560 mg/l antibody in a fed-batch air-lift fermentation system. Productivity is stable in the absence of MSX selection.
By clicking "Access Content" you agree to our Legal Disclaimer and the Lonza Privacy and Cookies Policy.

Latest content

Latest briefing from the Knowledge Center