Harvesting plasmid DNA from high-density E. coli fermentation

With emerging fields such as cell and gene therapy and DNA vaccines, the demand for plasmid DNA is growing. Plasmids are commonly produced from E. coli and can be difficult to harvest, as the fermentations are often grown to extremely high cell densities. Depth filters foul easily and need to be replaced, and centrifuges struggle to get low filtrate turbidity.

E. coli is a common production platform for plasmids.

FUNDALOOP® has had success in this area, and has been shown to filter a flocculated E. coli culture at roughly two times as fast as depth filtration. Most recently, a fermentation of 165 g/L was diluted by a factor of four with various buffers and flocculating agents, and subsequently filtered in multiple batches. The average flow rate achieved hovered around 900 LMH for cultures with a reduced pH and 400 LMH for cultures with crude pH, while filtrate clarity remained less than 10 NTU for all processed batches. Furthermore, product yield was over 90 %.

Interested to learn more about these findings, or perhaps you are struggling with E. coli harvesting and clarification yourself? Contact us for more information or to set up a trial!