A straightforward method to scale-up plasmid DNA intermediate recovery by tangential flow ultrafiltration

The interest in gene therapy and production of vaccines based on plasmid DNA (pDNA) has increased in recent years because they are novel techniques for the treatment or prevention of genetic diseases or infections. A typical bioprocess for the production of pDNA includes four stages: fermentation, primary recovery, intermediate recovery, and final purification. The crucial stage in the process is the capture of pDNA, as it is essential to provide good quality material for the purification stage. In this work, the behavior of tangential flow ultrafiltration (TFUF) in the intermediate recovery of plasmid pVAX1-LipL32 from lysates of E. coli ferments was investigated as an alternative to recovery operations that use chemical agents harmful to the environment. The concentration profile of the nucleic acids in both filtrate and retentate were determined by global analysis. The plasmid integrity during the recovery stages was verified at several intervals by means of electrophoresis analysis. A simple mathematical model was obtained to describe the process behavior that can be used as a straightforward method for the scale-up of the recovery process.