Tag: <span>amplification</span>

Beginning with the production of the very first ­recombinant deoxyribonucleic acid (DNA) molecule in 1972 and continuing through the ­following decade, DNA-focused molecular biology researchers firmly positioned themselves on the cutting edge of ­scientific inquiry. With each passing day, month and year, these researchers made ­significant leaps forward in understanding, modifying and manipulating the key roles that DNA plays in all living organisms. Some of the key milestones…

Nucleic Acids Research

Biopharmaceutical companies are constantly evaluating new methods for mammalian cell line development that provide benefits such as shorter timelines, improved consistency, higher production, better genetic stability, and increased flexibility. Each of these advantages extends a large cost benefit to companies as their recombinant protein products are moved from development into the clinic and finally to commercial launch. A versatile system has been developed that is capable of transferring genes of interest into a wide variety of mammalian host cells and offers a number of the above advantages over other methods. The system, which is referred to as GPEx‚ĄĘ (an acronym for ‚Äúgene product expression‚ÄĚ), utilizes replication-defective retroviral vectors, derived from Moloney murine leukemia virus (MLV) and pseudotyped with vesicular stomatitis virus G protein (VSV-G), to stably insert single copies of genes into dividing cells‚Ķ

Biologics Production Viral Vectors

Organizations developing biopharmaceuticals are often faced with the challenge of developing, as rapidly as possible, a production system for a recombinant protein or antibody intended for use in clinical trials. For expression of antibodies and other proteins with complex post-translational modifications, Chinese hamster ovary (CHO) cells are often the host of choice. However, isolation of CHO cell lines producing even moderate levels of a protein of interest is usually a lengthy process due to the need for at least one and usually several gene amplification steps. Gene amplification, which is usually accomplished through the dihydrofolate reductase (dhfr)/methotrexate system, is a requirement for most CHO expression vectors because the absolute expression level from each copy of an integrated expression plasmid is generally very low…

Biologics Production