Recombinant proteins, such as monoclonal antibodies, are produced in mammalian cell lines to introduce proper protein folding and post-translational modifications, which are essential for full biological activity. In both the industrial and academic environments, the use of recombinant proteins varies widely and, with it, the method of production. The amount of an antibody needed for a toxicity study is far greater than that needed by a research lab performing cellular assays, and the amount of effort put into the development of the protein will vary accordingly. There is no universal strategy for mammalian expression systems, and scientists often struggle to develop a suitable process from the myriad of choices at each step. Here, we elaborate on the various obstacles encountered when planning high-yield experiments to produce the recombinant proteins of interest. © 2018 by John Wiley & Sons, Inc.