Peristaltic pumps for the biopharma industry

Watson-Marlow Fluid Technology Group has supplied peristaltic pumps to Novasep for the latter’s Sius TFF Skid, a tangential flow filtration system used in the biopharmaceutical industry to separate and concentrate biomolecules according to their size. The skid is said to be the first on the market to offer a 100% single-use tangential flow filtration (TFF) solution, covering all tangential filtration requirements — from the R&D stages through to commercial production.

In tangential flow filtration, the fluid to be processed circulates across a porous membrane and, under pressure, passes through its pores. Molecules of a greater size than the pores remain in the retentate, whereas small molecules pass through the membrane into the permeate. The retentate circulates continuously in a loop travelling across the membrane which, for example, enables the molecules to be concentrated or facilitates buffer exchange (diafiltration).

The skid’s recirculation loop (retentate) is fed by a Watson-Marlow 520UN/R2 continuous tubing pump as part of diafiltration. A 620UN/RE LoadSure tube element pump is used to recirculate the retentate within the loop, providing low-pulse flow rates and a linear 4 bar displacement pressure, to enable easy setting of the system rentate valve.

The two pumps ensure cells are undamaged through excessive heat transfer and unwanted particulates are not introduced into the fluid stream. Furthermore, peristaltic technology eliminates cross-contamination risks.

“In this type of application, purity and quality are key factors,” said Jerome Chevalier, process engineer at Novasep. “Therefore, the cleaning phases are very important in order to ensure that the equipment complies with hygiene specifications. The Watson-Marlow pumps’ tubing provides high-purity, USP Class VI validated contact materials.”

Watson-Marlow tubes are pre-sterilised (gamma-irradiated) so that the user can eliminate the cleaning and validation phase without risk of contamination. This saves time and has a direct effect on operating costs.

“The second advantage of Watson-Marlow pumps is that they offer a high degree of precision, even at higher pressures,” added Chevalier. “This has enabled us to leave out the flow meter that we had planned originally.”