P53: False prediction of plasmid instability in an inducible recombinant E. coli fermentation

Maintaining a high degree of plasmid stability is important for a successful fermentation process.   If the recombinant cells lose their plasmids, they are not able to produce their target protein and hence raise concerns regarding the suitability of that particular production process.  Typical plasmid stability measurements use resistance markers, such as antibiotics, that are intrinsic to the plasmid DNA in the recombinant E. coli, and simple serial plating on agar with and without the appropriate antibiotic.  This study has shown that such a technique has the potential to falsely predict poor plasmid stability during an inducible E. coli fermentation process even though the cells still maintain their plasmid DNA at suitable levels.  This presentation uses orthogonal methods to determine the plasmid stability for the process in an effort to better understand the causality of the erroneous data from the standard plating results