ABSTRACT
The recombinant human coagulation factor IX (FIX) gene was cloned and expressed in a CHO cell line by recombinant DNA technology. A serum-free medium is used for the production of the recombinant FIX. The recombinant FIX is secreted in the medium and differs from the plasma-derived FIX in undergoing some post-translational modifications; these differences do not greatly affect the function of the protein.
