Patent ID: 7846724

Claim:
A method for the selection of a CHO cell that recombinantly produces a monoclonal antibody comprising human IgG1 or IgG3 heavy chain constant domains, wherein the heavy chain constant domains are glycosylated with a sugar chain at Asn297, wherein the sugar chain comprises at least 99% fucose, wherein if the sugar chain comprises N-glycolylneuraminic acid then the amount of N-glycolylneuraminic acid is 1% or less of the sugar chain and wherein if the sugar chain comprises N-terminal alpha-1,3-galactose then the amount of N-terminal alpha-1,3-galactose is 1% or less of the sugar chain; the method comprising: (1) cultivating a CHO cell transfected with an expression vector that encodes the heavy and light chains of a monoclonal antibody comprising human IgG1 or IgG3 heavy chain constant domains, wherein two DHFR alleles are deleted from the genome of the CHO cell; (2) applying DHFR selection pressure; (3) picking single clones; (4) expanding the clones; (5) producing antibodies from the clones; (6) analyzing glycosylation of the antibodies produced from the clones; and (7) selecting a clone that produces an antibody wherein the heavy chain constant domains are glycosylated with a sugar chain at Asn297, wherein the sugar chain comprises at least 99% fucose, wherein if the sugar chain comprises N-glycolylneuraminic acid then the amount of N-glycolylneuraminic acid is 1% or less of the sugar chain and wherein if the sugar chain comprises N-terminal alpha-1,3-galactose then the amount of N-terminal alpha-1,3-galactose is 1% or less of the sugar chain.